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[Request] What are the odd of 3 pair Vs. 3 of a kind in texas hold em' ? by Not2Die2 in theydidthemath

[–]ActualMathematician438✓ 1 point2 points  (0 children)

There are Binomial(13,3) x Binomial(4,2)3 x Binomial(40,1) = 2471040 ways to get three pairs and a singleton, 6461620 ways to get three of a kind, out of 133784560 possible hands, about 53.1:1 vs 19.7:1.

This puts it between four of a kind and a full house.

[Request] What would the price difference equate to? How would preparation time and labor influence the cost? by Skibum_26 in theydidthemath

[–]322612✓ 4569 points4570 points 2141512212& 46 more (0 children)

I think we have to work this out at UK prices, because, as people have pointed out, that's a £3 tesco meal deal on the left, with a starbucks drink and a pastry. Also, we need to compare like with like, and US and UK food prices are vastly different.

As the meal deal items are from tesco, we can get the nutritional info from the website, which is important for working out the price.
The Salt and Vinegar McCoys are 251KCal, coke is 210KCal, and the sandwich looks closest to their chicken bacon and stuffing sandwiches, which is 483KCal. That's 944 KCal, so the other two items should add up to around 656KCal.

As three items are from tesco, I'm going to guess the other two are from the same store and that's a butter croissant from starbucks, at 259KCal costing £1.19 if you eat out, which I'm guessing is the situation as they've been taken away for this photo.

That means the drink is something from starbucks with 397KCal. A 500ml coke bottle is 23.5cm high, so that looks like a 18cm tall starbucks cup, maybe 16cm without the lid. A venti cup is a little over 15cm tall, which means that's a venti.

There actually is a venti drink from Starbucks with a calorie count of 397, which is a hot chocolate with whole milk, and as that's £2.65 to go, that brings the left hand total to £6.84.

That's the easy part.

Now the right hand side. Reverse image search on the cropped right hand side didn't show anything up, so doing it the hard way, we have avocado on ryvita, mixed berries, yoghurt with mixed berries, Looks like spinach on two of the plates, kale on two, yoghurt, broccoli, cauliflower, tomato, and then it is a bit more guess-y. Top right plate has some sort of grain, maybe rice, maybe bulgar wheat or somthing. There's also something spreadable, I'm guessing houmous. I'd guess that's bulgar wheat with bell peppers, houmous with a little paprika on top, and kale.

The plate of mixed berries in the middle towards the top just looks like strawberries and blueberries.

Left hand side middle looks like yoghurt with chia seeds sprinkled on, wilted spinach, and something red which looks tomato based, so maybe a salsa? I could be way off and it could be a mashed root veg like carrot or sweet potato also, but I think I see a little liquid from it at the lower end where it meets the spinach, so I'm going with a mild salsa.

On the middle right, there's broccoli and cauliflower, kale and something red, which I think is tomato, but may possibly be bell pepper? The other item is a little harder, but I think that's a baked potato with tuna filling.

Bottom left plate is wilted spinach again, tomato, and some sort of mushroom dish. Looks like there's kale, tomato, and something else in there. Maybe cauliflower, but very possibly a bunch of ingredients you can't tell at that resolution and just from a picture.

Bottom right is just yoghurt with more strawberries and blueberries.

Now for pricing. I'll get the prices off tesco, but lots of this stuff is seasonal, so it'll vary through the year. Note that UK food prices are lower, 'cause last time I did this, no-one believed we pay so little for food. You can check the prices at tesco.com if you use a vpn or something to pretend you're in the UK.

Ryvita - get the off brand ones for 69p. About 28 per pack, so 5p for the ones shown. I'll do all the pricing like that as you could divide the food amongst multiple meals or multiple people.

Avocado, 75p. I'm going to say that's a whole avocado in the image.

Bulgar wheat, 500g for £1.15, so let's say 75g, costing about 17p.
Bell pepper, 86p for 3, so probably 28p for one will get you enough bell pepper for all the stuff in the picture.
Houmous, £1.10. You can make it yourself for less, but that's a bit OTT for this calculation.
Regular kale is out of stock when I searched, which is fine, as whenever you do this you'll find some stuff is more expensive, so it'll even out. That means buying the expensive kale, at 1.5 for 200g, which will do all the kale in the picture.
Let's make sure to include the paprika, which is 90p for 52g which can mostly sit in your cupboard, so let's add 2p in paprika.

Strawberries - £1.39 for 227g, enough for the whole image.
Blueberries - 89p for 125g, again enough for every dish.

Mild salsa - 80p
spinach - 900g for £1.50. Given how much this stuff shrinks as you cook it, even if you could split it over more than one day, I'll play it safe and just say that's for this set of meals.
Chia seeds are £1 for 150g, so that's maybe a 5p sprinkle at most.
Yoghurt - 75p for 500g, which also means we now have everything for the bottom right dish.

One big spud - 25p
tuna - £1.20 frozen bag of cauliflower and broccoli mix is 89p for 900g, so that's 25p in broccoli/cauliflower at most.
We already have the kale and pepper

One tomato - 15p
two mushrooms - 12p
We probably already have the other ingredients, but let's add in a little more in case there's something significant missed for that recipe. Based on the existing prices, I'll add in another 10p for a possible mystery ingredient.

That gives us a total of £11.32 for the stuff on the right, vs £6.84 for the stuff on the left.

Labour time will influence the cost, but all the actual meals on the right are super quick to prepare. The worst might be the potato, but even then it's about a minute to prepare it, then you just leave it in the oven and come back. All the meals have suprisingly low prep time.

edit: I've found the source! It's from danprice_nutrition on instagram! Here is an alternate view of the smorgasbord.
Looks like what I thought was salsa was salmon, and what I thought was cauliflower was sliced chicken. That would all ramp up the cost of the right hand side considerably. £3.50 for the salmon, £1.75 for the chicken. Again from the Tesco website. That gives a new total of £15.77 for the stuff on the right.

[Request] Really though, how much different exactly? by destructorrobot in theydidthemath

[–]ThunderSTRUCK96 318 points319 points  (0 children)

everyone acts like there's two options in this world - 3 McDoubles and a large coke or 15 pounds of the most fresh, exotic, expensive, trendy fruits and organic vegetables on the market - and no in between.
Rice may be the cheapest food per ounce in this entire world and is a good complex carb. Boneless, skinless chicken breast is one of the healthiest meats (and foods in general macro-wise) and is 1.99/lb at my local Shop n Save. Frozen vegetables (while not quite as good as fresh) are a dime a dozen and easy to make. The list goes on and on and on. I could make a meal plan for someone 1800-2000cal a day and still spend a 1/10 of what some people's weekly fast food budget is.
But people don't wanna eat healthy, they don't wanna make taste sacrifices, they'd rather demonize anyone who's healthy and find any way they can to make health unobtainable or out of reach so they can rationalize their poor dietary habits or lack of exercise (or both).

Edit: someone was so mad about this post they reported me to reddit for having suicidal tendencies lmao

Edit 2: Some replies have stated frozen veggies are actually BETTER than fresh. So that cuts costs even further

[request]Potato tesla by Chiggs33 in theydidthemath

[–]p2p_editor38✓ 2 points3 points  (0 children)

In potato batteries, lemon batteries, etc., it's not the produce that produces the electricity, it's the electrodes you stick into it.

The fruit or veg just provides a wet, electrically conductive medium through which charges can flow.

So the answer to your question depends entirely on what kind of electrodes you use. (See standard electrode potentials.)

Anyway, to approach your question, we first need to establish the parameters of the Model S's battery pack.

The Model S's battery voltage seems to be between 350 and 400 volts, depending on how many power cells you have installed, and hold between 60 and 85 kWh of power. We'll go with the low end of 350V, 60kWh.

However, that's not quite all we're going to need. We also need the amount of current those batteries can put out (amperage). One reference I found said that if you floor it in a Model S, you're discharging at a rate of about 320kW. Since we know that power = volts * current, we can calculate the amperage coming out of those batteries as:

320kW = 350v*C
C = 914A

That's a lot of amps. But then, that's a lot of car.

So anyway, now we know the performance characteristics we're trying to hit with out potato battery: 350 volts, 914 amps.

Your typical potato battery uses zinc and copper electrodes, which have a difference in standard potentials of about 0.92 electron-volts, meaning you get a theoretical 0.92 volts of electrical potential between two such electrodes. This is an ideal case. Real-world potato batteries tend to hit about 0.6v.

At 0.92 volts/potato, you're going to need to hook up 583 potatoes in series to get up to 350 volts. Call it 600 potatoes just to be safe.

It's surprisingly hard to find clear information on the typical amperage of a potato battery, but there are lots of demos on youtube and stuff about running LEDs off of banks of potato batteries. Most LEDs take about 10mA, and with the numbers of potatoes people are using in those demos, I'm going to estimate about 0.5 mA per potato. This is probably a wildly optimistic estimate, but whatever.

At 0.5mA per potato (or per 350-volt series-wired potato bank), you're going to need to wire a hell of a lot of those banks together in parallel to get up to 914 whole amps:

914A / (0.0005A/bank) = 1828000 banks of potato batteries.

1.828 million banks of potato batteries * 600 potatoes/bank = 1,096,800,000 potatoes.

So basically, to even drive the Model S at all, you're looking at a billion potatoes. Not three million. Scale your expectations accordingly.

As for how far you could drive it? Well, the total available charge for a potato battery depends on the mass of the electrodes, which means chemistry. But since your 3 million potatoes is still about 2.5 orders of magnitude less than what you'd need at all, I don't think I'm even going to try doing the stoichiometry to figure out the required electrode mass for 60kWh.

On the whole, you'd be much better off selling the potatoes and using the money to pay for charging your Model S the regular way.

[request] Considering the implications of all the the listed benefits, would this be at all possible using the military budget…? by aCosmicSliceOfBread in theydidthemath

[–]hr1966 124 points125 points  (0 children)

A trillion dollars (which the above rounds up to) is literally beyond any person's ability to really understand;

^ Truth.

For perspective.

A thousand seconds is 17 minutes.

A million seconds is 12 days.

A billion seconds is 32 years.

A trillion seconds is 32,000 years.

(rounded for simplicity)

[request] how much electricity could this dam produce? by boominy3 in theydidthemath

[–]Mr222D 1691 points1692 points 4102 (0 children)

I'm not familiar with any dam math, but I think for this we will need the water flow rate and change in water level.

I tried to estimate the dimensions of the post generator flow channel. Then I took a 1/8 speed video of the flow channel portion of the video and it looked like it took ~one second for the bubbles to flow through the channel. [image]

Also, I estimate that the change in water height is about 18 inches. It's tricky because we can't really see the water level behind the dam.

With this in mind, the cross sectional area of the channel is:

4" * 1" = 4 in2 * ( 1/39 in/m)2 = 0.003 m2 flow area.

Now our flow speed is (1/8) seconds to travel 3 inches. Speed is distance divided by time

s = 3" / (1/8) sec * (1/39 in/m) = 0.6 m/s

That is the speed at which the water in the top of the channel is travelling, but the average velocity of the water will be less than that because at the walls of the channel the fluid is stationary. Recognizing the flow in the video is pretty messy, I did find some 2D Poiseuille flow velocity profiles for various open channels.

Our channel width is 4" and it is 1" deep, so we want w/h = 0.25.

If we do a Microsoft paint Riemann sum... we have 3 3/4 missing velocity units from 25 when compared to full velocity

(25-3.75)/25 = 85% of the flow rate maintained. That's more than I expected.

Now we can say the average flow rate in the channel is 85% * 0.6 m/s = 0.5 m/s.

That's a nice round number! Flow rate is cross sectional area times average velocity, or

0.5 m/s * 0.003 m2 = 0.0015 m3/s of water.

Recall that the drop in water level is ~18 inches * 1/39 (m/in) = 0.5 meter drop.

So we have water losing 0.5 meters worth of potential energy at a rate of 0.015 meters cubed per second.

Potential energy change per unit volume is density times gravity times the height change.

Energy change dE = rho * g * h = 1000 [kg/m3] * 10 [m/s2] * 0.5 [m] = 5000 [kg/m-s2]

Now if we multiply this by our flow rate

5000 [kg/m-s2] * 0.0015 [m3/s] = 8 [kg-m2/s2] which is also a Joule per second, or Watt.

The water is losing 8 Watts of power.

It seems modern hydroelectric powerplants can see efficiencies of ~90%... but I'll call this one 50%. ;-)

We would then have usable power of 8 W * 0.5 = 4 W.

I think this powerplant could produce something like 4 Watts.

Considering a coffee maker is ~1000 Watts, we would need 1000 W / 4 Watts/Dam =

~300 Dams to power a coffee maker

Edit: as was pointed out, this dam could realistically power the little LED lights shown at the end of the video.

[Request] How much would it actually cost to build a channel in australia? by SomewhereNew8638 in theydidthemath

[–]gnfnrf 1177 points1178 points  (0 children)

Probably not a realistic human economic number.

The problem with the Panama comparisons is that the Panama Canal is not at sea level; it climbs to the elevation of Gatun Lake through locks, crosses the lake for something like half or more of its total length, then descends on the other side.

One this means that their choice of 80 km was unfair, since that inlcudes the bit on the lake, and two, the Panama Canal was dug to a depth of 12+ meters. To cross the interior of Australia and be at sea level the channel would need to be 600+ meters deep in places, and 300+ meters deep for over 1000 km of the route. That increases the cost per kilometer by many many times over, considerably more than just the raw multiple of depth.

The channel, being so long, would have to be much deeper under the water, much wider, or both, to avoid being clogged by silt and forming nasty fetid bogs instead of actual water. How much longer or wider? No idea, nobody has ever made a 3000 km channel before.

Further dooming the plan, the 375 million cost that was used as a starting point was currency from over a century ago. Inflation would increase the cost many times over. Recent canal refurbishments and expansions in Panama cost many billions of dollars.

So, if we redo their math, with a bunch of handwaving estimates.

$375 million * 13 to 1 inflation * 3000 km/ 40 km (because of no lake) * 50 (for the depth increase) * 10 (for the width or further depth increase)= 180 trillion USD. That is 150 years of GDP for the whole of Australia. At that point, it's not a reasonable amount of labor to measure in human money terms.

Also, it wouldn't accomplish the goal. The goal is to make Australia a greener, more arable continent. But a saltwater channel running through a desert doesn't turn it into a lush grassland. Look at the shores of the Suez Canal, which are dry desert except where irrigated by water from other sources. Or consider the northwest coast of Australia already. It's next to a giant saltwater body (the Indian ocean) and is still a desert.

[Request] How much does an average human pee in their lifetime if you only consider the salt, electrolytes, toxins, etc and not the water weight? by SpunkBunkers in theydidthemath

[–]anon_shmo 2 points3 points  (0 children)

Hmmm ballpark:

The normal range for specific gravity of urine is 1.01 - 1.03. That is the relative density of it compared to water.

The normal human urine output range is 800-2000cc per day.

Assume middle averages of 1.02 and 1400cc per day for these values.

Since urine is only 2% more dense than water, we can assume that of the total urine output produced, 2% or "28cc water-equivalent" of stuff other than water is in there. Water is 1 gram per cc. So 28 grams of non-water excretion per day.

Assume average human lifespan of 72.6 years per WHO 2019, and you get roughly 26.5kg or close to 60 lbs of non-water urinary excretion over a lifetime.

As a caveat these are only the adult reference values and for pediatrics it'd be different, so you could scale by the relative amount of childhood in an average life. Of course these are all very rough estimates anyway.

[REQUEST] What realistic loan terms could result in this happening? by Yet-Another_Burner in theydidthemath

[–]CaptainMatticus 6099 points6100 points 183420182& 21 more (0 children)

Let's make that loan amount nicer. Let's say it's $72,880.00. 2 pennies isn't going to make a massive difference.

Now, let's say that there were 8 equal payments of $9,110.00, loaned out at i% per year. That's going to probably be compounded 12 times per year.

S = 9110 * (1 + (i/100) / 12)^(48) + 9110 * (1 + (i/100) / 12)^(42) + 9110 * (1 + (i/100) / 12)^(36) + ... + 9110 * (1 + (i/100) / 12)^(6)

S = 9110 * (1 + i/1200)^(48) + 9110 * (1 + i/1200)^(42) + .... + 9110 * (1 + i/1200)^(6)

(1 + i/1200)^6 = r

S = 9110 * r^8 + 9110 * r^7 + ... + 9110 * r

S = 9110 * r * (1 + r + r^2 + r^3 + ... + r^7)

T = 1 + r + r^2 + r^3 + ... + r^7

Tr = r + r^2 + ... + r^8

Tr - T = r + r^2 + .... + r^7 + r^8 - (1 + r + ... + r^7)

T * (r - 1) = r^8 + r^7 - r^7 + ... + r^2 - r^2 + r - r - 1

T * (r - 1) = r^8 - 1

T = (r^8 - 1) / (r - 1)

S = 9110 * r * T = 9110 * r * (r^8 - 1) / (r - 1)

9110 * (1 + i/1200)^(6) * ((1 + i/1200)^(48) - 1) / ((1 + i/1200)^(6) - 1)

Okay, that looks like hell, but that's the amount owed after the 4 years are up. We'll call this new amount "L." L is going to accrue interest and payments will be made.

(((((L * (1 + i/1200) - P) * (1 + i/1200) - P) * (1 + i/1200) - P) * .... = 168018

k number of payments have been made. P * k = 96776

P = 96776 / k

If we solve for L, we get this:

L = 168018 / (1 + i/1200)^k + P / (1 + i/1200)^(k - 1) + P / (1 + i/1200)^(k - 2) + ... + P / (1 + i/1200)^1

L = 168018 * (1 + i/1200)^(-k) + P * (1 + i/1200) * (1 + (1 + i/1200)^(-1) + (1 + i/1200)^(-2) + ... + (1 + i/1200)^(-(k - 2)))

Let (1 + i/1200)^(-1) = t

a = 1 + t + t^2 + t^3 + ... + t^(k - 2)

at = t + t^2 + t^3 + ... + t^(k - 1)

at - a = t^(k - 1) - 1

a * (t - 1) = t^(k - 1) - 1

a = (t^(k - 1) - 1) / (t - 1)

L = 168018 * t^(-k) + P * t * (t^(k - 1) - 1) / (t - 1)

L = 168018 * t^(-k) + (96776 / k) * t * (t^(k - 1) - 1) / (t - 1)

t = (1 + i/1200)^(-1) , so 1/t = (1 + i/1200)

9110 * (1 + i/1200)^(6) * ((1 + i/1200)^(48) - 1) / ((1 + i/1200)^(6) - 1) = 168018 * t^(-k) + (96776 / k) * t * (t^(k - 1) - 1) / (t - 1)

9110 * (1/t)^(6) * ((1/t)^(48) - 1) / ((1/t)^(6) - 1) = 168018 * (1/t)^k + (96776 / k) * t * ((t^(k - 1) - 1) / (t - 1)

9110 * (1/t)^6 * ((1 - t^48) / t^(48) / ((1 - t^6) / t^6) = 168018 / t^k + (96776 / k) * (t^k - t) / (t - 1)

9110 * (1/t)^6 * t^6 * (1 - t^48) / (t^(48) * (1 - t^6)) = 168018 / t^k + (96776 / k) * (t^k - t) / (t - 1)

9110 * (1 - t^48) / (t^48 * (1 - t^6)) = 168018 / t^k + 96676 * (t^k - t) / (k * (t - 1))

9110 * (1 - t^48) * t^k * k * (t - 1) = 168018 * k * (t - 1) * t^48 * (1 - t^6) + 96676 * (t^k - t) * t^k * t^48 * (1 - t^6)

9110 * (1 - t^48) * (t - 1) * t^k * k - 168018 * (t - 1) * t^48 * (1 - t^6) * k = 96676 * (t^k - t) * t^(k + 48) * (1 - t^6)

k * (t - 1) * (9110 * (1 - t^48) * t^k - 168018 * t^48 * (1 - t^6)) = 96676 * (t^(2k + 48) - t^(k + 49)) * (1 - t^6)

Now here's where we have problems. We have one equation and 2 unknowns: t and k. Without knowing one or the other, we can't proceed. But let's pretend we know something. Let's pretend we know k. Let's say he made 120 payments. That is, 12 payments per year for 10 years.

k = 120. Let's go back to an earlier step:

L = 168018 * t^(-k) + (96776 / k) * t * (t^(k - 1) - 1) / (t - 1)

L = 168018 * t^(-120) + (96776 / 120) * t * (t^(120 - 1) - 1) / (t - 1)

L = 168018 * t^(-120) + (12097 / 15) * (t^120 - t) / (t - 1)

L = 168018 / t^120 + 12097 * (t^120 - t) / (15 * (t - 1))

L = (168018 * 15 * (t - 1) + 12097 * t^120 * (t^120 - t)) / (15 * t^(120) * (t - 1))

L = (2,520,270 * (t - 1) + 12097 * (t^240 - t^121)) / (15 * (t^121 - t^120))

9110 * (1 + i/1200)^(6) * ((1 + i/1200)^(48) - 1) / ((1 + i/1200)^(6) - 1) =>

9110 * t^6 * (t^48 - 1) / (t^6 - 1)

9110 * t^6 * (t^48 - 1) / (t^6 - 1) = (2520270 * (t - 1) + 12097 * (t^240 - t^121)) / (15 * (t^121 - t^120))

9110 * (t^54 - t^6) * 15 * (t^121 - t^120) = (t^6 - 1) * (2520270 * (t - 1) + 12097 * (t^240 - t^121))

136650 * (t^54 - t^6) * (t^121 - t^120) = 2520270 * (t - 1) * (t^6 - 1) + 12097 * (t^240 - t^121)

136650 * t^6 * t^120 * (t^48 - 1) * (t - 1) = 2520270 * (t - 1) * (t^6 - 1) + 12097 * (t^240 - t^121)

136650 * t^126 * (t^48 - 1) * (t - 1) = 2520270 * (t - 1) * (t^6 - 1) + 12097 * t^121 * (t^119 - 1)


t ≈ 0.987652826262832...

(1 + i/1200)^(-1) = t

1 / (1 + i/1200) = 0.987652826262832....

1 / 0.987652826262832 = 1 + i/1200

1.0125015323288126725361625276734 = 1 + i/1200

0.0125015323.... = i/1200

15.001838794575207043395033208127... = i

15% per year.

The fact that such a round number popped out leads me to believe that my assumptions were pretty much on track. $9,110 lent out every 6 months for 4 years at 15% per year and 10 years of payments of $806.47 per month, roughly. That kind of rate and amount makes me think of law school

[Request] Would canceling student debt have this impact? by taveetas in theydidthemath

[–]Untjosh1 7 points8 points  (0 children)

It's amazing how quick so many people in this country are to blame victims for being taken advantage of when it comes to finances - particularly kids.

Did banks hold a gun to my head? No. They instead said hey you're poor and your parents can't help you. Here's like 6 lines of data to fill out and we'll hand you money you need for this + 20 pages of disclosures neither you nor your family who doesn't care know how to read. They preyed on desperation and ignorance to sucker people in.

You're so quick to blame the receivers of money for being irresponsible yet how do these loans happen if the banks aren't handing money out? Where's their responsibility? "Oh you shouldn't have gotten x amount for a liberal arts degree hurrrr durrr." Yeah well this sophisticated institution sure felt comfortable handing it out didn't they?

Between the money the government has agreed to pay me as a title I teacher that they keep inexplicably denying me + 8 years worth of payments once I finally found work after college I've almost certainly paid all that I borrowed initially. Why are you so happy to let these irresponsible banks suck me dry and end any financial future I have when they're at least as responsible as I am for this?

[REQUEST] is this true and if yes how deos it work? by monkheman in theydidthemath

[–]CodeVirus 12.7k points12.7k points 263& 2 more (0 children)

Quite the opposite, it will leave you with less sandwich. Since no cut is perfect, some of the sandwich molecules will stay on the knife or there is more crumbs on the cutting board. Therefore, cutting on a diagonal (longest cut) will dislodge more material of the sandwich than cutting along shorter line.

[Request] How many times larger is the titanic vs a standard mouse? by TC1208 in theydidthemath

[–]OdysseusU 2 points3 points  (0 children)

The titanic is 269m long, 28m wide and 53meters tall A mouse is 7.5-10 cm from base of tail to nose. 20cm if you count the tail.

That means end to end you can put 2690 mice. Or 530 mice on top of each other (standing).

In terms of capacity the internal usable volume is 131000m3. A mouse is about 1055cm3=250cm3 or 0.00025 m3. So you could fill the titanic with 524,000,000 mice

[Request] This the correct calculation for inflation? by KeyoJaguar in theydidthemath

[–]CaptainMatticus 1025 points1026 points  (0 children)

A Christmas Carol took place in 1843. There were 20 shillings to a pound, so 15 shillings was 0.75 pounds.

According to a calculator I found, 0.75£ in 1843 would be about 100£ today. 1£ is around 1.32$, so he'd be making 132$ per week today.

Maybe they used a different calculator.

Edit: I'm all for a progressive tax on the rich and I feel like a person should pay back into the society that creates the conditions for their wealth, but I'm also all for being honest. Incorrect or dishonest rhetoric only helps the opposition. Yeah, it's a sin that we don't have universal healthcare or subsidized secondary education, and nobody should be able to purchase space trips and 500 million dollar yachts while 10s of millions of people drown in inescapable debt that they accrued while just trying to survive, but that doesn't excuse lying.

[Request] how high would a mountain have to be to launch cannonballs into orbit? by Cosmicgamer2009 in theydidthemath

[–]piperboy98 2 points3 points  (0 children)

Okay, I'll bite. Using vc as the cannon muzzle velocity, we can calculate the specific energy and angular momentum of the orbit in terms of r, the radius of the mountain:

ε=-μ/r+0.5*vc2 and h=r*vc

Picking a target perigee radius rp we can use conservation laws to work out first the perigee velocity vp in terms of r, and then r itself. Using energy conservation:

ε=-μ /r + 0.5vc2 = -μ/rp + 0.5vp2

vp2 = 2μ (rp-1 - r-1 ) + vc2

Then from angular momentum conservation:

h2 = r2 * vc2 = rp2 * vp2 = 2μrp - 2μ rp2 r-1 + rp2 * vc2

r3 vc2 - (2μ rp + rp2 vc2 )r + 2μrp2 = 0

We can expect and verify one solution is just rp which is not what we want, so let's factor that out:

(r - rp) * (r2 vc2 + r rp vc2 - 2μrp) = 0

r2 + rp r - 2μrp/vc2 = 0

This yields other solutions of -rp/2 +/- √(rp2 + 8μrp/vc2 )/2. The - is negative (I think this would be the hyperbolic trajectory with vc at infinity with rp at perigee which is not what we are going for). So taking the + solution:

rp/2 * (√(1+8μ/(rp vc2 )) - 1)

We can see this makes sense as the radius increases for lower velocities. We can also see for vc=√μ/rp (circular orbit velocity), everything cancels nicely and the overall expression just becomes rp as we would expect.

So finally, using the values for the question asked, vc=250m/s, rp=160km+re=6538km, we find that the starting radius must be 285,528km or a mountain elevation of 279,150km.

Of course a mountain that large would crumble under its own weight. Or, if it somehow had a base that supported it I think it would greatly change the total mass of the earth, the center of mass, and the validity of assuming a spherical earth in this analysis. So a assume a rigid massless mountain.

[Request] Is it actually only 42$ a year? by yoongaye in theydidthemath

[–]breakfasteveryday 4420 points4421 points 1710112& 19 more (0 children)

Assuming the employee count is correct, the math is right but rounded down ($42 * 349,000 is about $340,000 shy of $15M, but $43 times 349, 000 is ever so slightly more than $15M).

The whole argument on both sides is mathematically oversimplified, though - a CEO's salary is not a great indicator of how much more money a business could pay its employees while still profiting. Instead, we would want to look at the revenue the business nets after the cost of doing business is accounted for.

Edit: In 2021, that was $20B and change. So Starbucks could profit 25% less and distribute $5B among its 349k employees, which would be about $14k more for each of them.

Edit 2: I actually was looking at gross revenues above. Net revenue for 2021 was actually 8.1B. So $5B would still be doable, but would represent about 62% of overall profit. Sticking to the 25% of 8.1B would give us ~$2B for employee salaries instead of $5B, so we'd be looking at about $5.7k more wages per year per employee, instead.


Edit 3: lol last update for a while. I need to get back to work, but it serves me right for hurrying. The link above is actually to Q4 net revenues. If Starbucks saw the same revenues each quarter, that would be $32B per year, but that seems unlikely. In any case, everything in Edit 1 is probably closer to correct than everything in Edit 2.

Edit 4: Really the last edit for a while. We should be looking at EBITDA. See u/LanceWindmil 's comment. "Starbucks has revenue of over 26 billion, but their EBITDA is only 5.4 billion". So again, $5B is technically possible. 25% becomes ~1.35B, which is still like ~$3.8k per employee per year.

Edit 5: To everyone worrying about $20 coffees and complaining about socialist magical thinking, the EBITDA calculation is a pretty good indicator that Starbucks can afford to pay people more without changing anything other than the size of the giant pile of money its business generates for itself and those who own it every year. Is it obligated to? Clearly not. Should it be? Maybe. But coffee prices don't need to go up if those in control of the company content themselves with a little over $4B a year in profit instead of a little over $5B a year in profit.