Two children are playing with a roll of paper towels. One child holds the roll between the index fingers of her hands so that it is free to rotate, and the second child pulls at constant speed on the free end of the paper towels. As the child pulls the paper towels, the radius of the roll of remaining towels decreases.

a) How does the torque on the roll change with time?

increases

decreases

stays the same

b) How does the angular speed of the roll change in time?

increases

decreases

stays the same

Question

Physics

Giovanna Cruz

2 January, 04:43

Two children are playing with a roll of paper towels. One child holds the roll between the index fingers of her hands so that it is free to rotate, and the second child pulls at constant speed on the free end of the paper towels. As the child pulls the paper towels, the radius of the roll of remaining towels decreases.

a) How does the torque on the roll change with time?

increases

decreases

stays the same

b) How does the angular speed of the roll change in time?

increases

decreases

stays the same

+1

Answers (1)

Know the Answer?

Nicholas Armstrong · Answer 1

a) Decreases

b) Increases

c.) It's likely to break

Explanation:

a) The torque is as a result of friction, and also the magnitude is dependent on the normal force that exist between the surface in contact. The torque decrease because there is decrease in frictional force as the weight of the roll decrease

b.) The angular velocity will increase as radius o f the roll decrease because it is operating at constant speed.

c) if the child suddenly hit the roll, the papper will break, because it's angular acceleration might not be able to move along with the papper. Situation like this occur when there is large radius