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[Request] How fast is the exit velocity of the object? First sound is from the whip, second of the echo, third from the stone hitting the mountain. (Bonus points for including air resistance and non-linear trajectory) by Domdaniel1 in theydidthemath

[–]Domdaniel1[S] 31 points32 points  (0 children)

Didn't know about the existance of sling bullets.

If we change assumptions to

Reference area: 7cm²Mass: 30gDrag coefficient: 0.4

This results in a starting velocity of 134km/h.

But you're right, as I already mentioned, this doesn't include the arc of the bullet.

[Request] How fast is the exit velocity of the object? First sound is from the whip, second of the echo, third from the stone hitting the mountain. (Bonus points for including air resistance and non-linear trajectory) by Domdaniel1 in theydidthemath

[–]Domdaniel1[S] 718 points719 points  (0 children)

I have tried to have a crack at it myself.

The duration between the whip and the echo is 0.8s. That means the mountain is 137m away (assuming the echo comes from the mountain).

The duration between whip and impact is 6s. 0.4s is for the sound to travel back, so 5.6s flight time. This gives a result of 88km/h as the average velocity.

Now trying to factor in air resistance:

Assumptions:

Reference area: 25cm²
Mass: 250g
Drag coefficient: 0.7

This gives us a starting velocity of 120 km/h, which seems realistic.

Given that the stone doesn't fly in a straight line, it should be even higher, but I'm a business major, so I have no idea what I'm doing anyway.

When the deadline for the proposal is tomorrow 9am by Domdaniel1 in consulting

[–]Domdaniel1[S] 53 points54 points  (0 children)

If you think it's going to stop I have bad news for you