Chapter 7 quiz

Which of the following expressions is the unit of average angular acceleration?

• Radian (rad)

• Revolution (rev)

Which of the following is true about a rotating rigid body

• 
  Its centre of rotation is at rest

• 
  The centre of rotation is at the centre of mass

• 
  All points on the body are moving with the same linear velocity

• Every points in the body are moving with the same angular velocity

When the object tends to rotate in a clockwise rotation, the torque is

• Positive

• Negative

You and a friend are playing on the merry- go-round. You stand at the outer edge of the merry-go-round and your friend stands halfway between the outer edge and the center. Assume the rotation rate of the merry-go-round is constant. Who has the greatest tangential velocity?

• you

• your friend

• same

The number of complete revolutions per second is:

• frequency

• period

• torque

• rotational inertia

"Angle undergoes from a fixed reference line" this statement refer to

"Rate of change of angular displacement" this statement refer to

The easiest way to open a heavy door  is by applying the force

• Near the hinges

• 
  In the middle of the door

• At the edge of the door far from the hinges

• At the top of the door

Two forces are applied to a doorknob, perpendicular to the door. The first force is twice as large as the second force. The ratio of the torque of the first to the torque of the second is

• 1/4

• 1/2

• 2

• 4

Conditions for equilibrium are:

1st condition: net force = 0

2nd condition:net torque = 0

• True

• False