# Rigid Bodies including topics of power and torque.

1. Nov 30, 2005

### moo5003

Question:

"An airplane engine delivers 1.5x10^6 W at an angular velocity of 2400 rev/min."

A) Compute torque developed
B) If a drum of negligible mass, .5m in diameter, were attached to the motor shaft, and the power output of the engine were used to raise a weight hanging from a rope wrapped around the drum, how large a weight could be lifted?
C) With what velocity would it rise?

WORK DONE: (Almost nothing, kinda looking for where to start with this question)

I know since they gave us the rev/min that the angular velocity is (2400*2PIE)/60

Other then this.. I have no clue how to start this problem.

Solved: Thank you for your help Astronuc, you saved me hours of finding that.

Last edited: Nov 30, 2005
2. Nov 30, 2005

### Staff: Mentor

3. Nov 30, 2005

### moo5003

So power/angular velocity gives torque?
Proabably should have known that formula ^_^, just an analog with Pow=FV

4. Nov 30, 2005

### moo5003

Thank you for the help. I finished the problems.

A) 6000 Nm

B) m < or = to 2400KG

C) If exactly 2400KG then the velocity it is raised by equals the initial velocity given. (Due to Forces equaling one another there is no accel)

Hopefully there are no mistakes ^_^.

5. Nov 30, 2005

### Staff: Mentor

The weight on a line would have some linear velocity related to the angular velocity of the shaft.

$\omega$r = v or $\omega$ = v/r

http://hyperphysics.phy-astr.gsu.edu/hbase/rotq.html#rq