Recent content by bigtymer8700

am i messing up on calculating the ang velocity (w)?

here was my attempt Ki=136.125J Ui=1653.75J Kf=1/2mv^2+ 1/2Iw^2 Uf=0 for I am stuck on Kf Its a thin cylinder so I=MR^2 for w did i calculate it correct? v=wr so 11/.425= 25.8rad/s Ki +Ui=Kf + Uf so 136.125J +1653.75J= 1/2mv^2 + .4064*(25.8)^2 +0 from here i solved for...

A bicycle racer is going downhill at 11.0m/s when, to his horror, one of his 2.25kg wheels comes off when he is 75.0m above the foot of the hill. We can model the wheel as a thin-walled cylinder 85.0cm in diameter and neglect the small mass of the spokes. I need to get the velocity at the...

got it

i used the Ki + Ui=Kf + Uf Ki=0 Ui=mgy=73.5J Kf=1/2mv^2+1/2Iw^2 Uf=0 i got 73.5=1/2Iw^2+18.375 so 1/2(I)w^2=55.125J im stuck on Kf where i have to solve for the two unknowns I* w* i used v=rw to solve for w is that correct?

anyone know if I am doing this one rite?

A light string is wrapped around the outer rim of a solid uniform cylinder of radius .375m that can rotate without friction about an axle through its center. A 3.00 kg stone is tied to the free end of the string When the system is released from rest, you determine that the stone reaches a speed...

nvm yea you just use 0 for the start thanks guys

thats really where I am stuck on i solved the other parts of the problem asking for the atan arad at 60degrees and 120degrees but what value would i use for the start theta? 360 or 180, 0?

well if you use the w^2=Wo+2a(O-0o) its asking for the speed of the tip of the flywheel from the start so wouldn't the theta be 2xpi or just pi?

so that means w^2=0^2 +2(.600)(6.283) it comes out to be w=2.86 but it says its wrong

yea it would be double since its going back and forth thanks

Electric toothbrushes can be effective in removing dental plaque. One model consists of a head 1.10cm in diameter that rotates back and forth through a 70.0 angle 7600times/min . The rim of the head contains a thin row of bristles. its asking me the average angular speed in each direction of...

it says at the start so would thetaf and thetai be both 0?

A flywheel with a radius of 0.300 starts from rest and accelerates with a constant angular acceleration of 0.600/s^2. i know how to solve for the atan but not for arad which is arad=w^2/r it ask Compute the magnitude of the tangential acceleration, the radial acceleration, and the resultant...