Compute the torque developed by an airplane engine

[John O' Meara]

(a)Compute the torque developed by an airplane engine whose output is 2000hp at an angular velocity of 2400 rev/min. (b) If a drum of negligible mass, .5m in diameter, were attached to the motor shaft and the power output of the motor were used to raise a weight hanging from a rope wrapped around the drum, how large a weight could be lifted. (c) At what speed would it lift that weight.
My attempt (a) torque=P/w = 5.937*10^3N.m
(b) F=torque/r = 23.748*10^3N
(c) v=r*w. Any help on how to do part c, would be welcomed, thanks.

 

[Hootenanny]

(c) v=r*w. Any help on how to do part c, would be welcomed, thanks.

Your equation should work just fine

 

[kyle8921]

For part (c), we can use the formula for power, P = F*v, where P is power, F is force, and v is velocity. In this case, the power output of the engine is used to lift the weight, so we can rewrite the formula as P = (torque/r)*v. Substituting the values from part (b), we get:

23.748*10^3N = (5.937*10^3N.m / 0.25m) * v

Solving for v, we get v = 200 rev/min. This means that the weight would be lifted at a speed of 200 revolutions per minute.