# Few homework questions

1. Feb 13, 2005

### darkys

I'm having some trouble with a few rotational motion problems.

One question says... A wheel 33 cm in diameter accelerates uniformly from 240 rpm to 360 rpm in 6.5 s. How far will a point on the edge of the wheel travel in this time.

Is this asking for the angular displacement or the linear displacement?

The next one says A bowling ball of mass 7.3 kg rolls without slipping down a lane at 3.3m/s. (a) calculate its total kinetic energy. (b) Calculate its angular momentum

I can see how to get the total kinetic energy i think, but how do i find the angular momentum if i dont have the radius or the angular velocity?

Any help would be appreciated

2. Feb 13, 2005

### dextercioby

1.There's no linear movement,therefore u should compute the length of the circle the point travels in that time.
2.As for the last,i may be wrong,but you need the radius...

Daniel.

3. Feb 14, 2005

### BobG

The radius of a bowling ball is common knowledge and shouldn't need to be put into the problem. Virtually everybody knows that the radius of a bowling ball is 10.85 cm (plus or minus .05 cm).

Most people do know that, right? :uhh:

BTW, a 7.3 kg bowling ball isn't legal - it's about 44 grams too heavy. Check here for all you want to know about a bowling ball: http://www.bowl.com/downloads/pdf/USBCequipmanual2005_sectionIII.pdf" [Broken]

Last edited by a moderator: May 1, 2017
4. Feb 14, 2005

### dextercioby

Nope,Bob,i never did and never will play bowling.:tongue:

Daniel.