DidTheMath
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Request How far can sound travel?

I'm a writer that wrote herself a bullshit math problem that's over her paygrade(nothing) because I'm stupid so I decided to do the time honored tradition of asking reddit for help. So, assuming standard everything, how far can a 70 decibel sound wave from 30,000 to 40,000hz travel/be picked up by a receiver tuned to that frequency?

https://redd.it/1vwoled
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[request] how tall is this ice wall? Human at the front of the boat for reference.

https://redd.it/1vwp31m
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[Request] How dense and fast would a sword need to be to cut the head off a statue?
https://redd.it/1vwuhqp
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[Request] What would it take to give the entire Baltic Way a static shock, like in a school science experiment?
https://redd.it/1vwv43a
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[Request] What is the lifespan of a candle this size?
https://redd.it/1vwz8x5
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[Request] Population statistic
https://redd.it/1vx15ah
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[Other] Xavier’s math checks out
https://redd.it/1vx4e7e
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[Request] How much weight are you actually lifting on the pull-down side? Assume 80kg person using it.
https://redd.it/1vx5761
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[Request] Presuming this was for a 200-pound, six-foot male. How much time would it take for the hourglass to empty?
https://redd.it/1vx7wrh
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[Request] Disregarding the compression to upload, at 8gbps, can mumbo actually upload raw 32k streams?

https://redd.it/1vxfmez
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[Request] What’s the formal proof that 3 < 10?
https://redd.it/1vxiywp
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[Request] What is the shortest flight time possible (with timezones)
https://redd.it/1vxje8m
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[Request] A disease affects 1% of people. With a 99% sensitive and 99% specific test, what is the exact probability a positive test means you are actually sick?
/r/VouchPick/comments/1vwrw77/a_test_has_99_sensitivity_and_99_specificity_you/

https://redd.it/1vxfs6b
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[Request] Could this be done?
https://redd.it/1vxmx7d
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[Request] approximately how many Roman soldiers in this painting?
https://redd.it/1vxs629
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[Request] Why does this circle approximation still give 4 instead of pi?
https://redd.it/1vxtynk
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Self Which travels faster? Air molecule or a bullet?

(Is it the right way to do it?)

The higher the temperature the faster molecules travel. In fact temperature can be defined by how fast molecules move. It's called thermal velocity.

Assuming a bullet is shot at 500m/s - 1300m/s, at which temperature does the air move faster? For air, we need to account for it being a mixture of nitrogen and oxygen.

Here is the equation for the speed in 3D space: v = √(8(K_B T)/m).

k_B is Bolzmann constant

T is the temperature in Kelvin.

m is the mean mass of an air particle.

We are looking for a T that gives v = 1300m/s.

K_B = 1.380649 e\^-23 K\^-1 J
m = n1*m_N2 + n2*m_O2 = [0.78*(2*14) 0.21*(2*16)\] * 1.672 e\^-27 kg = 4.777 e\^-26 kg

T = mv\^2 / 8 K_B = (4.777 e\^-26 [kg\]) 1300\^2 [m\^2/s\^2\]/ 8 1.380649 e\^-23 [K\^-1 J\] = 731 K = 458°C
For v =500 m/s, T = 108 K = -165°C.

Therefore air particles in room temperature on average are in the range but not as fast as the fastest bullets.

https://redd.it/1vxvozd
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[Request] how fast is the cannonball moving and how much force does it strike Frank with?

https://redd.it/1vxwby5
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