(Multiple choice)

(1) True or False:

(a) If two vectors are parallel, their cross product must be zero.

(b) When a disk rotates about its symmetry axis, is along the axis.

(c) The torque exerted by a force is always perpendicular to the force.

(2)

Two vectors A and B have equal magnitude. Their cross product has the greatest magnitude if A and B are

(a) Parallel.

(b) Equal.

(c) Perpendicular.

(d) Anti parallel.

(e) At an angle of 45o to each other.

(3)

A particle of mass m is moving with speed v along a line that passes through point P. What is the angular momentum of the particle about point P?

(a) mv

(b) Zero

(c) It changes sign as the particle passes through point P.

(d) It depends on the distance of point P from the origin of coordinates.

(4)

A particle travels in a circular path.

(a) If its linear momentum p is doubled, how is its angular momentum affected?

(b) If the radius of the circle is doubled but the speed is unchanged, how is the angular momentum of the particle affected?

(5) True or false:

(a) The rate of change of a system's angular momentum is always parallel to the net external torque.

(b) If the net torque on a body is zero, the angular momentum must be zero.