1. a bee of mass M alights (lands softly) on a thin horizontal rod of mass 3M and length l which pivots frictionlessly about its center.(adsbygoogle = window.adsbygoogle || []).push({});

a) what torque did it exert

b) angular acceleration of rod when bee lands.

c) maximum angular velocity when bee reaches LOWEST point?

try:

a) torque = r x F = lmg

b) torque = I a

lmg = a 1/12 (3m) l squared

a = 4g / l

c) use kinematics??

2. atwood machine with frictionless 1.00 kg wheel and radium 0.1 is suspended with two masses on a massless rope. mass A is 2.0 kg. B is 1.5 kg.

a) Relate torque to net force on each of the two masses b) acceleration? c) tensions on THREE?? ropes?

attempt:

a) torque = r x F. but what is r?

b) i know how to do it for massless wheel. but how to incorporate a massed wheel?

c) dont understand the question.

3. A cylinder of mass M and R SLIDES with initial velocity of V0 down an inclinded plane with angle theta. mu is kinetic friction. a) what is acceleration of the objects Center of MASS B) torque on cylinder C) acceleration of cylinder? d) what speed will the object stop sliding and starts to roll?

attempt:

torque = mu m g R = I a

wR= v, for rolling

sigma = w/2 t

how should i go thinking about this problem?

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# Homework Help: Torque and angular momentum

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