# Physics Practice Questions Chapter 4

B) an automobile battery

Which has the greater mass?

A) a king-size pillow

B) an automobile battery

A) a king-size pillow

B) an automobile battery

mass

A kilogram is a measure of an object’s

D) all of these

Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much

A) inertia.

B) mass.

C) volume.

A) inertia.

B) mass.

C) volume.

E) none of these

Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has the same

A) mass.

B) volume.

C) weight.

E) none of these.

A) mass.

B) volume.

C) weight.

E) none of these.

mass

An object maintains its state of motion because it has

the gravitational attraction between you and the Earth.

Your weight is

inertia.

One object has twice as much mass as another object. The first object also has twice as much

the same

Compared to the mass of a certain object on Earth, the mass of the same object on the moon is

the mass of the car is independent of gravity.

Strange as it may seem, it is just as hard to accelerate a car on the moon as it is to accelerate the same car on Earth. This is because

3 minutes

An empty roller-coaster car at an amusement park takes 3 minutes to make its ride from start to finish.

Neglecting friction, a fully loaded car would take

Neglecting friction, a fully loaded car would take

force

The newton is a unit of

moon

In which case would you have the largest mass of gold? If your chunk of gold weighed 1 N on the

the one on the moon

An object weighs 30 N on Earth. A second object weighs 30 N on the moon. Which has the greater mass?

newtons

An object’s weight may properly be expressed in

magnitude and direction.

A force is a vector quantity because it has both

10 times as much as the force on the 1-kg book

A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is

double

An object is propelled along a straight-line path by a force.

If the net force were doubled, the object’s acceleration would

If the net force were doubled, the object’s acceleration would

increases

If an object’s mass is decreasing while a constant force is applied to the object, the acceleration

halves.

An object is propelled along a straight-line path in space by a force.

If the mass of the object somehow becomes twice as much, its acceleration

If the mass of the object somehow becomes twice as much, its acceleration

5 N

An object is pulled northward with a force of 10 N and southward with a force of 15 N.

The magnitude of the net force on the object is

The magnitude of the net force on the object is

10 N.

The force of friction on a sliding object is 10 newtons.

The applied force needed to maintain a constant velocity is

The applied force needed to maintain a constant velocity is

6 N

A 10-N falling object encounters 4 N of air resistance. The net force on the object is

0 N

A 10-N falling object encounters 10 N of air resistance. The net force on the object is

0 N

An apple weighs 1 N. When held at rest above your head, the net force on the apple is

1 N.

An apple weighs 1 N. The net force on the apple when it is in free fall is

D) all of these.

Which has zero acceleration? An object

A) at rest.

B) moving at constant velocity.

C) in mechanical equilibrium.

A) at rest.

B) moving at constant velocity.

C) in mechanical equilibrium.

is zero.

Whenever the net force on an object is zero, its acceleration

one third.

The maximum acceleration of a car while towing a second car twice its mass, compared to no towing, is

continue moving at 40 km/h in the absence of forces

Suppose you’re coasting on level ground in a car at 60 km/h and apply the brakes until you

slow to 40 km/h. When you suddenly release the brake, the car tends to

slow to 40 km/h. When you suddenly release the brake, the car tends to

increases.

A heavy block at rest is suspended by a vertical rope.

When the block is accelerated upward by the rope, the rope tension

When the block is accelerated upward by the rope, the rope tension

9.8 N

A 1-kg mass at the earth’s surface weighs

in mechanical equilibrium

If a non-rotating object has no acceleration, then we can say for certain that it is

add to equal your weight

When you stand at rest on a pair of bathroom scales, the readings on the scales will always

add up to equal your weight.

Hang from a pair of gym rings and the upward support forces of the rings will always

2000 N

A car has a mass of 1000 kg and accelerates at 2 meters per second per second.

What is the magnitude of the net force exerted on the car?

What is the magnitude of the net force exerted on the car?

1500 kg

A tow truck exerts a force of 3000 N on a car, accelerating it at 2 meters per second per second.

What is the mass of the car?

What is the mass of the car?

3.0

A girl 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 in meters per second per second?

If there are no other horizontal forces, what is the wagon’s acceleration in meters per second per second?

acceleration

If the mass of an object does not change, a constant net force on the object produces constant

the same

A force of 1 N accelerates a mass of 1 kg at the rate of 1 m/s2.

The acceleration of a mass of 2 kg acted upon by a net force of 2 N is

The acceleration of a mass of 2 kg acted upon by a net force of 2 N is

100 N

A bag of groceries has a mass of 10 kilograms and a weight of about

1 kg

The mass of a pet turtle that weighs 10 N is about

zero

The force required to maintain an object at a constant velocity in free space is equal to

has zero acceleration

An object following a straight-line path at constant speed

400 N

A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed

evenly over both scales. The reading on each scale is

evenly over both scales. The reading on each scale is

at the same time as the light block

Neglecting friction, a large block of ice and a small block of ice start sliding down an incline together.

The heavier block will get to the bottom

The heavier block will get to the bottom

500 N

When a woman stands at rest with two feet on a scale, the scale reads 500 N. When she gently lifts one foot,

the scale reads

the scale reads

10 times as much force

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

one would have to push with

10 times as much force on the heavier block

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

we would have to push with

the mass of the rocket decreases as fuel is burned

A rocket becomes progressively easier to accelerate as it travels upward from the ground mainly because

its weight

A rock is thrown vertically into the air. At the very top of its trajectory the net force on it is

9.8

A rock is thrown vertically into the air. At the top of its path, its acceleration in meters per second per second is

6 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?

What is the force of friction between the block and the surface?

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

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 from the first force.

The particle with both forces acting on it

The particle with both forces acting on it

2

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 in meters per second per second when taking off?

What is the jet’s acceleration in meters per second per second when taking off?

9.8 N

A 1-kg rock that weighs 9.8 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

the net force that acts on it when it is half way to the top of its path is

10 N

A 1-kg ball is thrown at 10 m/s straight upward. Neglecting air resistance, the net force that acts

on the stone when it is halfway to the top of its path is about

on the stone when it is halfway to the top of its path is about

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

If the truck were heavily loaded so that it had twice the total mass, the skidding distance would be

0.5 g

A skydiver of mass 100 kg experiences air resistance of 500 N, and an acceleration of about

12

An object released from rest on another planet requires one second to fall a distance of 6 meters.

What is the acceleration in meters per second per second due to gravity on this planet?

What is the acceleration in meters per second per second due to gravity on this planet?

220

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 in meters per second per second of the car?

What is the deceleration in meters per second per second of the car?

50 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

and comes to rest. It takes the block 2 seconds to stop. The stopping force acting on the block is about

1

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 in meters per second per second is

a friction force of 10 N. The acceleration of the block in meters per second per second is

4

If you are driving at 20 m/s and slam on your brakes and skid at 0.5 g to a full stop,

the skidding time in seconds is about

the skidding time in seconds is about

300 m

A 1000-kg automobile enters a freeway on-ramp at 20 m/s and accelerates uniformly up to 40 m/s in a time of 10 seconds. How far does the automobile travel during that time?

30 m/s

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

The speed of the car just before the brakes were applied was

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

distance of 2.5 meters in one second. On this planet, the rock has a weight of

2400 N

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?

against a friction force half its weight?

About 5000 N

The human body can, under certain conditions, withstand an acceleration of 10 g. What net

force would produce this acceleration of a 50-kg person?

force would produce this acceleration of a 50-kg person?

acceleration

If an object of constant mass experiences a constant net force, it will have a constant

the object accelerates in the direction of the applied force.

If more horizontal force is applied to a sliding object than is needed to maintain a constant velocity,

the object eventually slides to a stop

If less horizontal force is applied to a sliding object than is needed to maintain a constant velocity,

size and speed of the object

Two factors that greatly affect air resistance on falling objects are the

zero

When a falling object has reached its terminal velocity, its acceleration is

heavier object

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

Taking air resistance into consideration, the object to hit the ground first will be the

the light woman

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?

same-size parachutes at the same time. Which person will get to a state of zero acceleration first?

get a larger parachute.

A large and a small person wish to parachute at equal terminal velocities.

500 N

A skydiver, who weighs 500 N, reaches terminal velocity of 90 km/h.

The air resistance on the diver is then

The air resistance on the diver is then

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

elephant

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

The amount of air-resistance force is greater on the

decreases

When an object falls through the air, its velocity increases and its acceleration

decreases

A skydiver jumps from a high-flying plane. As her velocity of fall increases, her acceleration

decreases

A skydiver steps from a helicopter and falls for 5 seconds before reaching her terminal velocity.

300 N upward

A 500-N parachutist opens his chute and experiences an air resistance force of 800 N.

The net force on the parachutist is

The net force on the parachutist is

less

A ball is thrown vertically into the air. Because of air resistance, its speed when it returns to its starting level compared to its initial speed is

lead-filled ball

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

lead-filled ball

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. Air resistance just before they hit is actually greater for the

more

A ball is thrown vertically into the air. Because of air resistance, its time coming down compared to its time going up is

less than 5 s.

88) A ball thrown straight upward takes 10 seconds to go up and return to the ground. Because of air resistance, the time taken for the ball just to go up is

0.5 g

A falling skydiver of mass 100 kg experiences 500 N air resistance. The acceleration of the skydiver is

4 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?

the ratio of each object’s weight to its mass is the same

A feather and a coin will have equal accelerations when falling in a vacuum because

head first

A skydiver’s terminal velocity will be greatest if she falls