Posted by **Anderson** on Wednesday, April 18, 2007 at 6:51pm.

A tower clock has an hour hand 2.70 m long with a mass of 60.o kg, and a minute hand 4.50 m long with a mass of 100 kg. Calculate the total rotational kinetic energy of the two hands about the axis of rotation.

Sol: I know that Kr = 1/2Iw^2 or moment of inertia * omega squared. The problem is, it seems like I'm missing omega. I cannot seem to figure out how to get another angular (kinematics) into this problem. Perhaps there are too many unknown that I'm not aware of. Help would be appreciated. thx

teacher's answer: 1.04 E -3 J

Omega for the minute hand is 2PI/minute

Omega for the hour hand is 2PI/hour.

change both to radians per second.

Total rotational energy = 1/2 Ihour*wh^2 + 1/2 Imin*wm^2

## Answer This Question

## Related Questions

- physics - A particular tower clock similar to Big Ben has an hour hand 2.70 m ...
- Geometry (math) - The 100-foot clock tower in Rome, Georgia is more than 100 ...
- maths - the minute hand of a clock is 9cm long. the hour hand clock is 2/3 times...
- physics - The hour hand and the minute hand for the famous Parliament clock ...
- math - The point of the minute hand on a church clock travels 180 cm faster than...
- physics - At 15 minutes past the hour, a 50 g mouse runs up a grandfather clock ...
- physics - At 15 minutes past the hour, a 50 g mouse runs up a grandfather clock ...
- matha - the minute hand of a clock is 9m long. the hour hand clock is 2/3 times ...
- algebra - A clock has a minute hand that is 14 feet long and an hour hand that ...
- PreCalc - Consider the tip of each hand of a clock. Find the linear velocity in ...

More Related Questions