ch. 2 quiz
An elephant and a feather fall from a tree through the air to the ground below. The amount of air-resistance force is greater on the Select one: a. elephant. b. feather. c. is the same on each
a. elephant
A 10-N block and a 1-N block lie on a horizontal frictionless table. To push them with equal acceleration, we would have to push with Select one: a. equal forces on each block. b. 10 times as much force on the heavier block. c. 10 squared or 100 times as much force on the heavier block. d. one-tenth as much force on the heavier block. e. none of these
b. 10 times as much force on the heavier block
A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is Select one: a. 0 N. b. equal to the weight of the puck. c. the weight of the puck divided by the mass of the puck. d. the mass of the puck multiplied by 10 m/s/s. e. none of these
0 N
A sack of potatoes weighing 200 N falls from an airplane. As the velocity of fall increases, air resistance also increases. When air resistance equals 200 N, the sack's acceleration in meters per second per second is Select one: a. 0. b. 5. c. 10. d. infinite. e. none of these
a. 0
A large and a small person wish to parachute at equal terminal velocities. The larger person will have to Select one: a. get a larger parachute. b. jump lightly. c. pull upward on the supporting strands to decrease the downward net force. d. jump first from the plane. e. none of these Incorrect
a. get a larger parachute
A large and a small person wish to parachute at equal terminal velocities. The larger person will have to Select one: a. get a larger parachute. b. jump lightly. c. pull upward on the supporting strands to decrease the downward net force. d. jump first from the plane. e. none of these
a. get a larger parachute
A force is a vector quantity because it has both Select one: a. magnitude and direction. b. mass and acceleration. c. action and reaction counterparts.
a. magnitude and direction
An object maintains its state of motion because it has Select one: a. mass. b. weight. c. speed. d. acceleration. e. all of these Incorrect
a. mass
The force required to maintain an object at a constant velocity in free space is equal to Select one: a. zero. b. the mass of the object. Incorrect c. the weight of the object. d. the force required to stop it. e. none of these
a. zero
A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is Select one: a. the same as the force on the 1-kg book. b. 10 times as much as the force on the 1-kg book. c. zero.
b. 10 times as much as the force on the 1-kg book.
A girl pulls on a 10-kg wagon with a constant force of 30 N. What is the wagon's acceleration in meters per second per second? Select one: a. 0.3 b. 3.0 c. 10 d. 30 e. 300
b. 3.0
If an object falls with constant acceleration, the velocity of the object must Select one: a. be constant also. b. continually change by the same amount each second. c. continually change by varying amounts, depending on its speed. d. continually decrease. e. none of these
b. continually change by the same amount each second.
An object is propelled along a straight-line path by a force. If the net force were doubled, its acceleration would Select one: a. quadruple. b. double. c. stay the same. d. halve. e. none of these
b. double
Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the tendency of the rock is to Select one: a. continue to follow a circular path. b. follow a straight-line path.
b. follow a straight-line path.
A pair of tennis balls fall through the air from a tall building. One ball is regular and the other is filled with lead pellets. The ball to reach the ground first is the Select one: a. regular ball. b. lead-filled ball. c. same for both.
b. lead-filled ball
The maximum acceleration of a car while towing a second car twice its mass, compared to no towing, is Select one: a. one-half. b. one-third. c. one-fourth. d. the same. e. none of these
b. one-third.
When a falling object has reached its terminal velocity, its acceleration is Select one: a. constant. b. zero. c. g.
b. zero
Ten seconds after starting from rest, a freely falling object will have a speed of about Select one: a. 10 m/s. b. 50 m/s. c. 100 m/s. d. more than 100 m/s.
c. 100 m/s
A push on a 1-kg brick accelerates the brick. Neglecting friction, to equally accelerate a 10-kg brick, one would have to push with Select one: a. just as much force. b. 10 times as much force. c. 100 times as much force. d. one-tenth the amount of force. e. none of these
c. 100 times as much force.
A baseball player bats a ball with a force of 1000 N. The ball exerts a reaction force against the bat of
c. 1000N
One-half second after starting from rest, a freely falling object will have a speed of about Select one: a. 20 m/s. b. 10 m/s. c. 5 m/s. d. 2.5 m/s. e. none of these
c. 5 m/s.
A 10-N falling object encounters 4 N of air resistance. The magnitude of the net force on the object is Select one: a. 0 N. b. 4 N. c. 6 N. d. 10 N. e. none of these
c. 6 N
A 10-N falling object encounters 4 N of air resistance. The magnitude of the net force on the object is Select one: a. 0 N. b. 4 N. c. 6 N. d. 10 N. e. none of these
c. 6 N
It takes 6 s for a stone to fall to the bottom of a mine shaft. How deep is the shaft? Select one: a. about 60 m b. about 120 m c. about 180 m d. more than 200 m
c. about 180 m
A skydiver steps from a helicopter and falls for 5 s before reaching her terminal velocity. During this 5-s interval, her acceleration Select one: a. is constant. b. increases. c. decreases. d. is zero. e. none of these
c. decreases
A car traveling at 100 km/h strikes an unfortunate bug and splatters it. The force of impact is greater on the Select one: a. bug. b. car. c. is the same for both
c. is the same for both
A Mack truck and a Volkswagen traveling at the same speed collide head-on. The impact force is greatest on the Select one: a. Volkswagen. b. Mack truck. c. is the same for both
c. is the same for both.
