Help with physics I homework please...lol. solved again, thanks.

[Techie333]

I know it may seem elementary to some of you guys, but how do you find the moment of inertia of a coin given radius, volume, mass??

and also, if a force is applied tangentially to a penny giving it angular accel of 1 rad/s^2, what would ang. accel of nickel be given same force? Or rather how do I find it?

 

[AgaBoogaBoo]

buy the answer book online

I've always thought of doing that since they're probably available....

Seriously, no clue to your answer

 

[Techie333]

dam, i gotta turn this in tomorrow by 9am! anybody, please?

 

[Whitecloak]

I = 1/2 MR^2 ?

 

[Darien]

http://scienceworld.wolfram.com/physics/MomentofInertia.html

For your second question, you need to know the mass.

 

[Techie333]

ya, thanx i figured it out!

 

[Techie333]

wait..about the second part...if penny = .2kg and nickel is .3kg, and ang. accel of penny is 1 rad/s^2, would ang. accel of nickel be 1.5 (1x(3/2)) rad/s^2???

 

[BigPoppa]

t=Ia(alpha). So the force applied is equal to the moment of inertia times the angular acceleration. You should be able to find it from there.

 

[Techie333]

thanks, i hope u guys are right...i really need an A on this to keep an A+ in the class....

 

[Darien]

small hint: if you use the same force on a heavier object, the heavier object *should* move slower

thanks, i hope u guys are right...i really need an A on this to keep an A+ in the class....

wtf. first 3 physics grades i had in college: b-, c+, b-

A+??~~?~?!?!?!?!?!

 

[So]

Originally posted by: Darien
small hint: if you use the same force on a heavier object, the heavier object *should* move slower

(assuming same shape...)

thanks, i hope u guys are right...i really need an A on this to keep an A+ in the class....

wtf. first 3 physics grades i had in college: b-, c+, b-

A+??~~?~?!?!?!?!?!

NOTE: He said nothing about college.

I did pull A's in 3/4 of my physics classes (and I think I'm done w/ 'em)