A. A delivery person waiting for an elevator lowers a carton onto a dolly.
B. When the elevator doors open, the delivery person lifts the dolly over the threshold of the elevator.
C. The delivery person pushes the dolly to the back of the elevator while pressing a floor button.
D. The door closes and the elevator moves from the 10th to the 4th floors.
a. 0.05.0 s
b. 5.010.0 s
D. 15.020.0 s
A. acceleration is zero
B. velocity is zero
Both acceleration and velocity are zero.
D. none of these choices
a. The acceleration varies.
b. The acceleration is zero.
c. The acceleration is constant.
d. The acceleration increases then becomes constant.
a. midway on the way up
b. at the top of its path
c. the instant it leaves the catcher’s hand
d. the instant before it arrives in the catcher’s mitt
D. frame of reference
A. each equal to half the magnitude of the vector.
B. independent of the orientation of the vector.
D. vector quantities.
A. ax = ay = -g.
B. ax = constant and vy = constant.
C. vx = constant and ay = -g.
D. vx = constant and vy = constant.
A. The velocity must be zero.
B. The velocity must be constant.
C. The acceleration must be zero.
D. The momentum must be constant
A. 5800 N
B. 14 700 N
C. 775 N
D. 13 690 N
A. at rest
B. being accelerated.
C. moving with a constant velocity
D. losing mass.
A. The car increases speed and changes direction.
B. The car increases speed but does not change direction.
C. The car maintains its speed but changes direction.
D. The car maintains both its speed and direction.
A. The nail exerts a force on the hammer; the hammer exerts a force on the wood.
B. The hammer exerts a force on the nail; the wood exerts a force on the nail.
C. The hammer exerts a force on the nail; the nail exerts a force on the hammer.
D. The hammer exerts a force on the nail; the hammer exerts a force on the wood.
A. whenever a force acts on the object.
B. whenever a force is perpendicular to the displacement of the object.
C. whenever a force causes a displacement of the object.
D. whenever a net force acts on the object.
A. kinetic energy involves position, and potential energy involves motion.
B. kinetic energy involves motion, and potential energy involves position.
C. although both energies involve motion, only kinetic energy involves position.
D. although both energies involve position, only potential energy involves motion.
A. the sum of kinetic energy and gravitational potential energy.
B. the sum of kinetic energy and elastic potential energy.
C. the sum of kinetic energy and all relevant forms of potential energy.
D. the sum of all forms of energy.
A. The object with the higher velocity will have less momentum if the masses are equal.
B. The more massive object will have less momentum if its velocity is greater.
C. The less massive object will have less momentum if the velocities are the same.
D. The more massive object will have less momentum if the velocities are the same.
A. equal in magnitude and direction.
B. equal in magnitude and opposite in direction.
C. in the same direction but of different magnitudes
D. in opposite directions and possibly of different magnitudes.
C. Perfectly elastic
D. perfectly inelastic
A. elastic collision
B. inelastic collision
C. perfectly elastic collision
D. perfectly inelastic collision
A. circular force
b. centripetal acceleration
c. centripetal force
d. centrifugal force
A. two objects always exert gravitational forces on each other.
B. the force of gravity depends on the mass and the distance between the two objects.
C. all objects fall at different rates on earth.
D. both a and b.
a. It would increase by a factor of 2.
b. It would increase by a factor of 4.
c. It would decrease by a factor of 2.
d. The speed would not change.
A. The closer the force is to the axis of rotation, the less torque is produced.
B. The closer the force is to the axis of rotation, the easier it is to rotate the object.
C. The farther the force is from the axis of rotation, the harder it is to rotate the object.
D. The farther the force is from the axis of rotation, the less torque is produced.