Exam 3 Flashcards
A bug riding on the end of a fan blade experiences a centripetal acceleration of constant (nonzero)
magnitude. What must be true about the angular velocity of the fan?
A. It is increasing.
B. It is decreasing.
C. It is zero.
D. It is constant but nonzero.
D. It is constant but nonzero.
A second bug is riding at the midpoint of the same fan blade (i.e. half as far from the axis of rotation).
Which of the following motion quantities are the same for both bugs?
A. centripetal acceleration
B. tangential velocity
C. angular velocity
D. None of the above
C. angular velocity
A fan has a constant positive angular acceleration. Which of the following is true?
A. The net torque acting on it is positive and constant.
B. Its angular velocity is positive and constant.
C. Its angular momentum is positive and constant.
D. Its rotational kinetic energy is positive and constant.
A. The net torque acting on it is positive and constant.
A cylindrical container is filled to the brim with an unknown liquid. The top surface of the liquid is
exposed to the air. The absolute pressure at the bottom of the container does NOT depend on
A. the height of the container.
B. the density of the liquid.
C. the diameter of the container.
D. the local atmospheric pressure.
C. the diameter of the container.
A bug riding on the end of a fan blade experiences a constant positive angular acceleration. This
means that the _____________ is also constant.
A. centripetal acceleration
B. magnitude of its tangential velocity
C. angular velocity
D. magnitude of its tangential acceleration
D. magnitude of its tangential acceleration
A second bug is riding at the midpoint of the same fan blade (i.e. half as far from the axis of rotation).
Which of the following motion quantities is different for this bug?
A. angular acceleration
B. centripetal acceleration
C. angular velocity
D. All of the above
B. centripetal acceleration
A fan has a constant negative torque acting on it. Which of the following is true?
A. Its angular velocity is negative and constant.
B. Its angular momentum is negative and constant.
C. Its angular acceleration is negative and constant.
D. Its rotational kinetic energy is negative and constant.
C. Its angular acceleration is negative and constant
A child riding by himself on a spinning merry-go-round moves toward the center of the
merry-go-round. No one is pushing, and friction is negligible. The angular momentum of the child-merry-go-round system
A. stays the same.
B. increases.
C. decreases.
D. More information needed
The angular speed of the child-merry-go-round system
A. stays the same.
B. increases.
C. decreases.
D. More information needed
A. stays the same.
B. increases.
A cylindrical container is filled to the brim with an unknown liquid. The top surface of the liquid is
exposed to the air. The absolute pressure at the bottom of the container does NOT depend on
A. the material the container is made from.
B. the local atmospheric pressure.
C. the height of the container.
D. the density of the liquid.
A. the material the container is made from.
A bug riding on the end of a fan blade experiences a tangential acceleration of constant magnitude in
the same direction as its tangential velocity. Which of the following is true?
A. Its angular acceleration is zero.
B. Its centripetal acceleration has a constant magnitude.
C. Its angular speed is increasing.
D. Its tangential speed is constant.
C. Its angular speed is increasing.
A second bug is riding at the midpoint of the same fan blade (i.e. half as far from the axis of
rotation). The magnitude of its tangential acceleration is ____________ that of the first bug.
A. half
B. twice
C. the same as
D. None of the above
A. half
If the net torque acting on an object is zero, its ____________ must also be zero.
A. angular acceleration
B. angular velocity
C. angular momentum
D. All of the above
A. angular acceleration
A child is riding by herself on a merry-go-round that is rotating counter-clockwise.
She walks away from the center of the merry-go-round. No one is pushing, and friction is negligible.
Which of these quantities decreases for the child+merry-go-round system?
A. rotational inertia
B. angular velocity
C. angular momentum
D. None of the above
Which of these quantities stays the same for the child+merry-go-round system?
A. rotational inertia
B. angular velocity
C. angular momentum
D. None of the above
B. angular velocity
C. angular momentum
A bug riding on the end of a fan blade experiences a nonzero centripetal acceleration and zero
tangential acceleration. Which of the following is true?
A. Its angular acceleration is nonzero.
B. Its angular velocity is zero.
C. Its angular velocity is constant.
D. Its tangential speed is increasing.
C. Its angular velocity is constant.
A second bug is riding at the midpoint of the same fan blade (i.e. half as far from the axis of
rotation). The magnitude of its centripetal acceleration is ____________ that of the first bug.
A. half
B. twice
C. the same as
D. None of the above
A. half
