Physics Chapter 4- Week 3

A 10-N falling object encounters 10 N of air resistance. The net force on the object is Select one: a. 0 N. b. none of these c. 6 N. d. 4 N. e. 10 N.

0 N.

An apple weighs 1 N. When the apple is held at rest above your head, the net force on the apple is Select one: a. 0 N. b. 1 N. c. None of these d. 0.1 N. e. 9.8 N.

0 N.

An object released from rest on another planet requires one second to fall a distance of 6 meters. What is the acceleration due to gravity on this planet? Select one: a. 6 m/s2 b. 15 m/s2 c. 3 m/s2 d. 12 m/s2 e. None of these

12 m/s2

A car has a mass of 1000 kg and accelerates at 2 m/s2. What net force is exerted on the car? Select one: a. 500 N b. none of these c. 2000 N d. 1500 N e. 1000 N

2000 N

In which case would you have the largest mass of gold? If your chunk of gold weighed 1 N on the Select one: a. Moon. b. planet Jupiter. c. Earth.

Moon.

Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has the same Select one: a. All of these b. None of these c. mass. d. volume. e. weight.

None of these

A light woman and a heavy man jump from an airplane at the same time and open their same-size parachutes at the same time. Which person will get to the ground first? Select one: a. Both should arrive at the same time. b. The heavy man c. The light woman d. not enough information

The heavy man

A light woman and a heavy man jump from an airplane at the same time and open their same-size parachutes at the same time. Which person will get to a state of zero acceleration first? Select one: a. The light woman b. The heavy man c. not enough information d. Both should arrive at the same time.

The light woman

If more horizontal force is applied to a sliding object than is needed to maintain a constant velocity, the object Select one: a. accelerates in the direction of the applied force. b. experiences greater friction. c. accelerates opposite the direction of the applied force. d. None of these

accelerates in the direction of the applied force.

A constant net force on a rail-road car produces constant Select one: a. velocity. b. both of these c. acceleration. d. neither of these

acceleration.

If an apple experiences a constant net force, it will have a constant Select one: a. acceleration. b. position. c. speed. d. velocity. e. more than one of these

acceleration.

If you double the net force on an object, you'll double its Select one: a. All of these b. acceleration. c. speed. d. velocity.

acceleration.

Which has the greater mass? Select one: a. both the same b. an automobile battery c. a king-size pillow

an automobile battery

At equilibrium on a bathroom weighting scale, the downward pull of gravity on you is balanced by Select one: a. your weight. b. your mass. c. an upward support force.

an upward support force.

Neglecting friction, a small and a large block of ice begin sliding down an incline together. The larger block reaches the bottom Select one: a. before the small block. b. after the small block. c. at the same time as the small block.

at the same time as the small block.

A heavy ball hangs by a string, with a second string attached to its bottom (Figure 4.8 in your book). A quick pull on the bottom string breaks the Select one: a. top string. b. top or bottom string equally. c. bottom string.

bottom string.

You drive your car at a constant 60 km/h along the highway. You apply the brakes until the car slows to 40 km/h. If at that moment you suddenly release the brakes, the car tends to Select one: a. momentarily regain its higher initial speed. b. decrease in speed if no other forces act. c. continue moving at 40 km/h.

continue moving at 40 km/h.

Suppose a particle is being accelerated through space by a 10-N force. Suddenly the particle encounters a second force of 10 N in the opposite direction. The particle with both forces acting Select one: a. decelerates gradually to a halt. b. is brought to a rapid halt. c. theoretically tends to accelerate toward the speed of light. d. None of these e. continues at the speed it had when it encountered the second force.

continues at the speed it had when it encountered the second force.

Suzie Skydiver jumps from a high-flying plane. As her velocity of fall increases, her acceleration Select one: a. increases. b. remains unchanged regardless of air resistance. c. decreases.

decreases.

If less horizontal force is applied to a sliding object than is needed to maintain a constant velocity, the object Select one: a. accelerates in the direction of the applied force. b. None of these c. eventually slides to a stop. d. experiences decreased friction.

eventually slides to a stop.

The newton is a unit of Select one: a. force. b. inertia. c. mass. d. density.

force.

A large and a small person wish to parachute at equal terminal velocities. The larger person should Select one: a. pull upward on the supporting strands to decrease the downward net force. b. jump lightly. c. get a larger parachute. d. jump first from the plane.

get a larger parachute.

A coconut and a bird's feather fall from a tree through the air to the ground below. The force of air resistance is Select one: a. greater on the coconut. b. greater on the feather. c. the same on each.

greater on the coconut.

If the mass of a cart is quickly loaded to have twice the mass while a propelling force remains constant, the cart's acceleration Select one: a. halves. b. doubles. c. stays the same. d. quadruples. e. none of these

halves.

A skydiver's terminal velocity will be greatest if she falls Select one: a. head first. b. with her parachute open. c. lying flat on her stomach. d. lying flat on her back.

head first.

Two objects of the same size, but unequal weights are dropped from a tall tower. Taking air resistance into consideration, the object to hit the ground first will be the Select one: a. heavier object. b. Both hit at the same time. c. lighter object. d. not enough information

heavier object.

A heavy rock and a light rock of the same size are falling through the air from a tall building. The one that encounters the greatest air resistance is the Select one: a. same for both b. heavy rock. c. light rock.

heavy rock.

If a non-rotating object has no acceleration, then we can say for certain that it is Select one: a. at rest. b. All of these c. moving at constant non-zero velocity. d. in mechanical equilibrium. e. None of these

in mechanical equilibrium.

When the bottom string is pulled slowly in the heavy-ball-and-strings demonstration (Figure 4.8 in your book), tension Select one: a. in the top string is due to your pull plus the weight of the ball. b. in the bottom string is zero. c. is about the same in both strings.

in the top string is due to your pull plus the weight of the ball.

If an object's mass is decreasing while a constant force is applied to the object, the acceleration Select one: a. decreases. b. remains the same. c. increases.

increases.

An object with twice as much mass as another object has twice as much Select one: a. acceleration due to gravity. b. All of these c. speed. d. inertia.

inertia.

A heavy block at rest is suspended by a vertical rope. When the block accelerates upward by the rope, the rope tension Select one: a. equals its weight. b. is greater than its weight. c. is less than its weight.

is greater than its weight.

Two factors that greatly affect air resistance on falling objects are frontal area and Select one: a. speed. b. mass. c. weight.

speed.

Your weight as measured on your bathroom scale is Select one: a. the force due to gravity on you. b. equal to your mass. c. a property of mechanical equilibrium. d. All of these

the force due to gravity on you.

Compared to the mass of an apple on Earth, the mass of the apple on the Moon is Select one: a. six times as much. b. zero. c. the same. d. one sixth as much.

the same.

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 becomes Select one: a. infinite. b. 10 m/s2. c. None of these d. 0 m/s2. e. 5 m/s2.

0 m/s2.

Scotty Skydiver of mass 100 kg experiences air resistance of 500 N, and an acceleration of about Select one: a. greater than 0.5 g. b. 0.5 g. c. 0.2 g. d. 0.4 g. e. 0.3 g.

0.5 g.

An apple at rest weighs 1 N. The net force on the apple when it is in free fall is Select one: a. 0 N. b. None of these c. 9.8 N. d. 0.1 N. e. 1 N.

1 N.

The mass of a pet turtle that weighs 10 N is about Select one: a. 1 kg. b. 100 kg. c. 10 kg. d. 1000 kg. e. None of these

1 kg.

A 10-kilogram block is pushed across a horizontal surface with a horizontal force of 20 N against a friction force of 10 N. The acceleration of the block is Select one: a. 5 m/s2. b. 10 m/s2. c. 1 m/s2. d. 2 m/s2. e. None of these

1 m/s2.

A 1-kg ball is thrown at 10 m/s straight upward. Neglecting air resistance, the net force that acts on the ball when it is halfway to the top of its path is about Select one: a. 7.5 N. b. 1/2 N. c. 10 N. d. 5 N. e. 1 N.

10 N.

A 1-kg mass at the Earth's surface weighs Select one: a. 10 N. b. 1 N. c. None of these d. 5 N. e. 12 N.

10 N.

A 1-kg rock that weighs 10 N is thrown straight upward at 20 m/s. Neglecting air resistance, the net force that acts on it when it is half way to the top of its path is Select one: a. more than 10 N. b. 10 N. c. less than 10 N.

10 N.

The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is Select one: a. less than 10 N. b. more than 10 N. c. 10 N.

10 N.

A rock is thrown vertically into the air. At the top of its path, its acceleration is Select one: a. zero. b. 10 m/s2. c. greater than 10 m/s2. d. between 0 and 10 m/s2.

10 m/s2.

A 10-N block and a 1-N block lie on a horizontal frictionless table. To impart equal horizontal accelerations, we would have to push the heavier block with Select one: a. None of these b. 1/10 as much force. c. an equal force. d. 10 times as much force. e. 10 squared or 100 times as much force.

10 times as much force.

A push on a 1-kg brick accelerates it. Neglecting friction, equally accelerating a 10-kg brick requires Select one: a. one-tenth the amount of force. b. None of these c. 10 times as much force. d. 100 times as much force. e. just as much force.

10 times as much force.

A 10-kg brick and a 1-kg apple are dropped in a vacuum. The force of gravity on the brick is Select one: a. zero. b. the same as the force on the apple. c. 10 times more than the force on the apple. d. one-tenth as much as on the apple.

10 times more than the force on the apple.

A bag of groceries that has a mass of 10 kilograms weighs about Select one: a. greater than 1000 N. b. 1 N. c. 1000 N. d. 10 N. e. 100 N.

100 N.

The mass of a lamb that weights 110 N is about Select one: a. 11 kg. b. 1 kg. c. 110 kg. d. 1100 kg. e. None of these

11 kg.

A tow truck exerts a force of 3000 N on a car, which then accelerates at 2 m/s2. What is the mass of the car? Select one: a. 1500 kg b. 3000 kg c. 1000 kg d. none of these e. 500 kg

1500 kg

A jumbo jet has a mass of 100,000 kg. The thrust for each of its four engines is 50,000 N. What is the jet's acceleration when taking off? Select one: a. 0.25 m/s2 b. 1 m/s2 c. 4 m/s2 d. 2 m/s2 e. None of these

2 m/s2

A car traveling at 22 m/s comes to an abrupt halt in 0.1 second when it hits a tree. What is the deceleration of the car? Select one: a. 880 m/s2 b. need more information c. 220 m/s2 d. 800 m/s2 e. 110 m/s2

220 m/s2

What horizontally-applied force will accelerate a 400-kg crate at 1 m/s2 across a factory floor against a friction force half its weight? Select one: a. 2400 N b. None of these c. 2000 N d. 600 N e. 1600 N

2400 N

Nellie pulls on a 10-kg wagon with a constant horizontal force of 30 N. If there are no other horizontal forces, what is the wagon's acceleration? Select one: a. 10 m/s2 b. 300 m/s2 c. 3.0 m/s2 d. 30 m/s2 e. 0.3 m/s2

3.0 m/s2; (NOT 30 BE CAREFUL)

A 2000-kg car experiences a braking force of 10,000 N and skids to a stop in 6 seconds. The speed of the car just before the brakes were applied was Select one: a. 45 m/s. b. 1.2 m/s. c. 15 m/s. d. 30 m/s. e. None of these

30 m/s.

A 500-N parachutist opens his chute and experiences an air resistance force of 800 N. The net force on the parachutist is then Select one: a. 500 N downward. b. 800 N downward. c. 300 N downward. d. 500 N upward. e. 300 N upward.

300 N upward.

A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is Select one: a. more than 3000 N. b. 300 N. c. 3000 N. d. 30 N.

3000 N.

An astronaut on another planet drops a 1-kg rock from rest. The astronaut notices that the rock falls 2 meters straight down in one second. On this planet, how much does the rock weigh? Select one: a. 5 N b. 4 N c. 10 N d. 1 N

4 N

If you are driving at 20 m/s and slam on your brakes and skid at 0.5g to a full stop, the skidding time is about Select one: a. 6 s. b. 4 s. c. 5 s. d. greater than 6 s. e. 3 s.

4 s.

A mobile phone is pulled northward by a force of 10 N and at the same time pulled southward by another force of 15 N. The resultant force on the phone is Select one: a. 150 N. b. 25 N. c. 0 N. d. 5 N.

5 N.

An astronaut on another planet drops a 1-kg rock from rest and finds that it falls a vertical distance of 2.5 meters in one second. On this planet, the rock has a weight of Select one: a. 4 N. b. 1 N. c. 5 N. d. 3 N. e. 2 N.

5 N.

A 10-kilogram block with an initial velocity of 10 m/s slides 10 meters across a horizontal surface and comes to rest. It takes the block 2 seconds to stop. The stopping force acting on the block is about Select one: a. None of these b. 5 N. c. 50 N. d. 10 N. e. 25 N.

50 N.

Phil stands at rest with both feet on a scale that reads 500 N. When he gently lifts one foot, the scale reads Select one: a. 500 N. b. less than 500 N. c. more than 500 N.

500 N.

Suzie Skydiver, who weighs 500 N, reaches terminal velocity of 90 km/h. The air resistance on Suzie is then Select one: a. 250 N. b. 90 N. c. 410 N. d. None of these e. 500 N.

500 N.

The human body can withstand an acceleration of 10 g under certain conditions. What net force would produce this acceleration for a 50-kg person? Select one: a. 5000 N b. 2500 N c. 25,000 N d. None of these e. 500 N

5000 N

A block is dragged without acceleration in a straight-line path across a level surface by a force of 6 N. What is the force of friction between the block and the surface? Select one: a. need more information b. more than 6 N c. less than 6 N d. 6 N

6 N

A 10-N falling object encounters 4 N of air resistance. The net force on the object is Select one: a. None of these b. 0 N. c. 4 N. d. 6 N. e. 10 N.

6 N.

Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much Select one: a. mass. b. None of these c. inertia. d. All of these e. volume

All of these

Recall Galileo's Leaning Tower experiment. With negligible air resistance, a heavy and a light object fall Select one: a. to the ground in equal times. b. with the same increases in speed. c. All of these d. with equal accelerations.

All of these

Which has zero acceleration? An object Select one: a. None of these b. at rest. c. in mechanical equilibrium. d. moving at constant velocity. e. All of these

All of these

If the net force on a cart is tripled, the cart's acceleration Select one: a. is one third. b. is three times as much. c. is more than three times as much. d. is two thirds.

is three times as much.

A skydiver steps from a helicopter and falls for a few seconds until terminal velocity is reached. Thereafter, until he opens his parachute, his acceleration Select one: a. increases. b. decreases. c. is constant. d. None of these e. is zero.

is zero.

Whenever the net force on an object is zero, its acceleration Select one: a. may be less than zero. b. may be more than zero. c. is zero.

is zero.

A single brick falls with acceleration g. The reason a double brick falls with the same acceleration is Select one: a. None of these b. an experimental fact tested many times. c. its ratio of force to mass is the same. d. that in free fall all accelerations are g.

its ratio of force to mass is the same.

Two tennis balls fall through the air from a tall building. One of them is filled with lead pellets. The ball to reach the ground first is the Select one: a. regular ball. b. same for both c. lead-filled ball.

lead-filled ball.

A ball thrown straight upward takes 10 seconds for its up-and-down round trip. Because of air resistance, the time taken for the ball just to go up is Select one: a. less than 5 s. b. more than 5 s. c. 5 s.

less than 5 s.

A ball is thrown upwards and caught when it returns. Compared with its initial speed and in the presence of air resistance, the speed with which it is caught is always Select one: a. more. b. can't be determined. c. less. d. the same.

less.

A ball is thrown vertically into the air. Because of air resistance, its speed when it returns to its starting level compared with its initial speed is Select one: a. more. b. the same. c. less.

less.

A kilogram is a measure of an object's Select one: a. force. b. both of these c. neither of these d. mass.

mass.

A rock is thrown vertically into the air. At the top of its path the net force on it is Select one: a. more than mg. b. mg. c. less than mg.

mg.

A ball is thrown vertically into the air. Because of air resistance, its time coming down compared to its time going up is Select one: a. the same. b. less. c. more.

more.

An object's weight is properly expressed in units of Select one: a. meters. b. newtons. c. kilograms. d. cubic centimeters.

newtons

A car by itself is capable of a certain maximum acceleration. When it tows a car of the same mass, its maximum acceleration is Select one: a. one third. b. none of these c. the same. d. one half. e. one fourth.

one half.

A car by itself is capable of a certain maximum acceleration. When it tows a twice-as-massive car, its maximum acceleration is Select one: a. one third. b. one fourth. c. one half. d. the same. e. none of these

one third.

When you stand at rest with your left foot on one bathroom scale and your right foot on a similar scale, each of the scales will Select one: a. show readings that when added equal your weight. b. cancel your weight. c. read your weight. d. read half your weight.

show readings that when added equal your weight.

Strange as it may seem, it is just as difficult to accelerate a car on a level surface on the Moon as it is here on Earth because Select one: a. neither of these b. the weight of the car is independent of gravity. c. both of these d. the mass of the car is independent of gravity.

the mass of the car is independent of gravity.

When a constant and sustained upward force acts on a rocket, its acceleration increases mainly because Select one: a. No way, for acceleration would be constant. b. the mass of the rocket decreases as fuel is burned. c. gravity becomes weaker with increased distance.

the mass of the rocket decreases as fuel is burned.

A rock weighs 30 N on Earth and another rock weighs 30 N on the Moon. Which rock has the greater mass? Select one: a. They have the same mass. b. not enough information c. the one on Earth d. the one on the Moon

the one on the Moon

A feather and a coin will have equal accelerations when falling in a vacuum because Select one: a. the ratio of both the feather's and coin's weight to mass is the same. b. None of these c. the force of gravity does not act in a vacuum. d. their velocities are the same. e. the force of gravity is the same for each in a vacuum.

the ratio of both the feather's and coin's weight to mass is the same.

A bowling ball and a baseball accelerate equally when falling in a vacuum because Select one: a. the ratio of their weights to mass is the same. b. their velocities are the same. c. None of these d. the force of gravity is the same for each in a vacuum. e. the force of gravity does not act in a vacuum.

the ratio of their weights to mass is the same.

A force of 1 N accelerates 1-kg box at the rate of 1 m/s2. The acceleration of a 2-kg box by a net force of 2 N is Select one: a. the same. b. twice as much. c. half as much. d. None of these

the same.

The brakes of a speeding truck are slammed on and it skids to a stop. If the truck were heavily loaded so that it had twice the total mass, the skidding distance would be Select one: a. 4 times as far. b. the same. c. half as far. d. 1.5 times as far. e. twice as far.

the same.

A heavy ball hangs by a string, with a second string attached to its bottom. A slow pull on the bottom string breaks the Select one: a. bottom string. b. top or bottom string equally. c. top string.

top string.

A boulder following a straight-line path at constant velocity has Select one: a. zero acceleration. b. a net force acting upon it in the direction of motion. c. no forces acting on it. d. None of these

zero acceleration.

The force required to maintain a constant velocity for an astronaut in free space is equal to Select one: a. zero. b. the force required to stop the astronaut. c. None of these d. the mass of the astronaut. e. the weight of the astronaut.

zero.

When a falling object has reached its terminal velocity, its acceleration is Select one: a. zero. b. g. c. constant.

zero.