Question

Disregarding the force of gravity, the maximum velocity v of a rocket is given by v = t ln M, where t is the velocity of the exhaust and M is the ratio of the mass of the rocket with fuel to its mass without fuel. A solid propellant rocket has an exhaust velocity of 2.5 kilometers per second. Its maximum velocity is 7.5 kilometers per second. Find its mass ratio M.
Make sure you include the model.

Answer 1

7.5 = 2.5 ln M
ln M = 3
m = e^3 = 20.08553692

Answer 2

im not sure about the model

Answer 3

Thank you.

Answer 4

np

Answer 5

Could you help with another?

Answer 6

sure

Answer 7

Thanks.

Answer 8

The electrical resistance r of a wire varies directly with its length l and inversely with the square of its diameter d. If 200 m of wire with diameter 6 mm has a resistance of 16 ohms, what is the resistance of 300 m of wire with a diameter of 8 mm?

Answer 9

u might want to post that im not sure :(

Answer 10

Okay. Thanks anyways.