PHY 121 Ch. 4 Conceptual Questions
and answers rated A+ 2025
(T/F?) If the rockets of a space ship in outer space (far from all gravity)
suddenly lose power and go off, the space ship will gradually slow to a stop. -
correct answer ✔False
(T/F?) If a 5.0 kg box is pulled simultaneously by a 10.0 N force and a 5.0 N
force, then its acceleration must be 3.0 m/s2. - correct answer ✔False
(T/F?) A bucket is being lowered by a rope with a constant downward
acceleration. The tension in the rope must be equal to the weight of the
bucket. - correct answer ✔False
(T/F?) An elevator suspended by a vertical cable is moving downward but
slowing down. The tension in the cable must be greater than the weight of the
elevator. - correct answer ✔True
(T/F?) A tennis ball following a parabolic trajectory without air resistance has
two forces acting on it; gravity downward and a force keeping it moving
forward. - correct answer ✔False
A dog is standing in the tail bed of a pickup truck. The tail bed is coated with
ice, causing the force of friction between the dog and the truck to be zero. The
truck is initially at rest, and then accelerates to the right, moving along a flat
road. As seen from a stationary observer (watching the truck move to the
right), the dog - correct answer ✔does not move left or right, but the back of
the truck moves towards the dog.
and answers rated A+ 2025
(T/F?) If the rockets of a space ship in outer space (far from all gravity)
suddenly lose power and go off, the space ship will gradually slow to a stop. -
correct answer ✔False
(T/F?) If a 5.0 kg box is pulled simultaneously by a 10.0 N force and a 5.0 N
force, then its acceleration must be 3.0 m/s2. - correct answer ✔False
(T/F?) A bucket is being lowered by a rope with a constant downward
acceleration. The tension in the rope must be equal to the weight of the
bucket. - correct answer ✔False
(T/F?) An elevator suspended by a vertical cable is moving downward but
slowing down. The tension in the cable must be greater than the weight of the
elevator. - correct answer ✔True
(T/F?) A tennis ball following a parabolic trajectory without air resistance has
two forces acting on it; gravity downward and a force keeping it moving
forward. - correct answer ✔False
A dog is standing in the tail bed of a pickup truck. The tail bed is coated with
ice, causing the force of friction between the dog and the truck to be zero. The
truck is initially at rest, and then accelerates to the right, moving along a flat
road. As seen from a stationary observer (watching the truck move to the
right), the dog - correct answer ✔does not move left or right, but the back of
the truck moves towards the dog.
