Question 1

According to Newton's third law of motion,

Accepted Answer

A) there is no such thing as a single force acting on an object. 
B) for every force there is an equal and opposite reaction force, but each acts on a different object. 
C) action and reaction forces need not be equal, but must act in opposite directions. 
D) action and reaction forces must be equal, but need not act in opposite directions. 
A) there is no such thing as a single force acting on an object. 
B) for every force there is an equal and opposite reaction force, but each acts on a different object. 
C) action and reaction forces need not be equal, but must act in opposite directions. 
D) action and reaction forces must be equal, but need not act in opposite directions. B

Question 2

The sun exerts a gravitational force on the earth and the earth exerts a gravitational force on the sun.The force the earth exerts

Accepted Answer

A) is the action force. 
B) is the reaction force. 
C) can be considered either as the action or as the reaction force. 
D) is not part of an action-reaction pair because the earth and sun are not in contact with each other. 
A) is the action force. 
B) is the reaction force. 
C) can be considered either as the action or as the reaction force. 
D) is not part of an action-reaction pair because the earth and sun are not in contact with each other. C

Question 3

A car starts from rest and reaches a speed of 15 m/s in 10s.Its acceleration is

Accepted Answer

A) 0.67 m/s2. 
B) 1.5 m/s2. 
C) 6.7 m/s2. 
D) 15 m/s2. 
A) 0.67 m/s2. 
B) 1.5 m/s2. 
C) 6.7 m/s2. 
D) 15 m/s2. B

Question 4

The time needed for a car whose speed is 60 km/h to travel 800 m is

Accepted Answer

A) 0.48 min. 
B) 0.8 min. 
C) 4.5 min. 
D) 13 min. 
A) 0.48 min. 
B) 0.8 min. 
C) 4.5 min. 
D) 13 min.

Question 5

A 500-g ball moves in a circle 40 cm in radius at a speed of 4 m/s.The centripetal force on the ball is

Accepted Answer

A) 10 N. 
B) 20 N. 
C) 40 N. 
D) 80 N. 
A) 10 N. 
B) 20 N. 
C) 40 N. 
D) 80 N.

Question 6

A crane exerts an upward force of 200 N on a 20-kg crate.The crate's upward acceleration is

Accepted Answer

A) 0. 
B) 0.2 m/s2. 
C) 10 m/s2. 
D) 98 m/s2. 
A) 0. 
B) 0.2 m/s2. 
C) 10 m/s2. 
D) 98 m/s2.

Question 7

If the moon were half as far from the earth as it is now, the gravitational force it exerts on the earth would be

Accepted Answer

A) one-quarter its present value. 
B) half its present value. 
C) twice its present value. 
D) four times its present value. 
A) one-quarter its present value. 
B) half its present value. 
C) twice its present value. 
D) four times its present value.

Question 8

The escape speed needed for an object to leave the earth permanently

Accepted Answer

A) depends on its mass. 
B) is less than the minimum speed it needs to become an earth satellite. 
C) is equal to the minimum speed it needs to become an earth satellite. 
D) is more than the minimum speed it needs to become an earth satellite. 
A) depends on its mass. 
B) is less than the minimum speed it needs to become an earth satellite. 
C) is equal to the minimum speed it needs to become an earth satellite. 
D) is more than the minimum speed it needs to become an earth satellite.

Question 9

On a rainy day the maximum frictional force between a car's tires and a certain level road surface is reduced to half its usual value.The maximum safe speed for rounding a curve is

Accepted Answer

A) unchanged. 
B) reduced to 25% of its usual value. 
C) reduced to 50% of its usual value. 
D) reduced to 71% of its usual value. 
A) unchanged. 
B) reduced to 25% of its usual value. 
C) reduced to 50% of its usual value. 
D) reduced to 71% of its usual value.

Question 10

The mass of a 2,200-lb elephant is

Accepted Answer

A) 224 kg. 
B) 1,000 kg. 
C) 4,840 kg. 
D) 21,560 kg. 
A) 224 kg. 
B) 1,000 kg. 
C) 4,840 kg. 
D) 21,560 kg.

Question 11

The mass of a sack of potatoes whose weight is 200 N is

Accepted Answer

A) 20.4 kg. 
B) 91 kg. 
C) 210 kg. 
D) 440 kg. 
A) 20.4 kg. 
B) 91 kg. 
C) 210 kg. 
D) 440 kg.

Question 12

A snail travels 45 cm in 20 min.Its average speed is

Accepted Answer

A) 2.25 cm/h. 
B) 15 cm/h. 
C) 90 cm/h. 
D) 135 cm/h. 
A) 2.25 cm/h. 
B) 15 cm/h. 
C) 90 cm/h. 
D) 135 cm/h.

Question 13

When its brakes are applied, a car moving at 10 m/s undergoes an acceleration of -1.2 m/s2.How far does the car travel before it comes to a stop?

Accepted Answer

A) 42 m. 
B) 78 m. 
C) 83 m. 
D) 124 m. 
A) 42 m. 
B) 78 m. 
C) 83 m. 
D) 124 m.

Question 14

Which one or more of the following pairs of displacements cannot be added to give a resultant displacement of 2 m?

Accepted Answer

A) 1 m and 1 m. 
B) 1 m and 2 m. 
C) 1 m and 3 m. 
D) 1 m and 4 m. 
A) 1 m and 1 m. 
B) 1 m and 2 m. 
C) 1 m and 3 m. 
D) 1 m and 4 m.

Question 15

A hole is drilled to the center of the earth and a ball is dropped into it.When the ball is at the earth's center, compared with their respective values at the earth's surface,

Accepted Answer

A) its mass and weight are the same. 
B) its mass and weight are both 0. 
C) its mass is the same and its weight is 0. 
D) its weight is the same and its mass is 0. 
A) its mass and weight are the same. 
B) its mass and weight are both 0. 
C) its mass is the same and its weight is 0. 
D) its weight is the same and its mass is 0.

Question 16

When its brakes are applied, a car moving at 10 m/s undergoes an acceleration of -1.2 m/s2.In the next 5 s the car travels

Accepted Answer

A) 15 m. 
B) 32 m. 
C) 35 m. 
D) 47 m. 
A) 15 m. 
B) 32 m. 
C) 35 m. 
D) 47 m.

Question 17

Relative to what she weighs on the earth, an astronaut visiting another planet

Accepted Answer

A) weighs less. 
B) weighs the same. 
C) weighs more. 
D) Any of these choices, depending on the planet. 
A) weighs less. 
B) weighs the same. 
C) weighs more. 
D) Any of these choices, depending on the planet.

Question 18

The weight of an object is

Accepted Answer

A) the same everywhere on the earth's surface. 
B) greater at the poles than at the equator. 
C) less at the poles than at the equator. 
D) Any of these choices, depending on the phase of the moon. 
A) the same everywhere on the earth's surface. 
B) greater at the poles than at the equator. 
C) less at the poles than at the equator. 
D) Any of these choices, depending on the phase of the moon.

Question 19

The speed of an object moving in a circle is doubled.The centripetal force needed is

Accepted Answer

A) one-quarter as much as before. 
B) half as much as before. 
C) twice as much as before. 
D) four times as much as before. 
A) one-quarter as much as before. 
B) half as much as before. 
C) twice as much as before. 
D) four times as much as before.

Question 20

In the first 3 s after a car starts from rest with an acceleration of 4 m/s2 it will travel

Accepted Answer

A) 6 m. 
B) 12 m. 
C) 18 m. 
D) 72 m. 
A) 6 m. 
B) 12 m. 
C) 18 m. 
D) 72 m.

According to Newton's third law of motion,

The sun exerts a gravitational force on the earth and the earth exerts a gravitational force on the sun.The force the earth exerts

A car starts from rest and reaches a speed of 15 m/s in 10s.Its acceleration is

The time needed for a car whose speed is 60 km/h to travel 800 m is

A 500-g ball moves in a circle 40 cm in radius at a speed of 4 m/s.The centripetal force on the ball is

A crane exerts an upward force of 200 N on a 20-kg crate.The crate's upward acceleration is

If the moon were half as far from the earth as it is now, the gravitational force it exerts on the earth would be

The escape speed needed for an object to leave the earth permanently

On a rainy day the maximum frictional force between a car's tires and a certain level road surface is reduced to half its usual value.The maximum safe speed for rounding a curve is

The mass of a 2,200-lb elephant is

The mass of a sack of potatoes whose weight is 200 N is

A snail travels 45 cm in 20 min.Its average speed is

When its brakes are applied, a car moving at 10 m/s undergoes an acceleration of -1.2 m/s².How far does the car travel before it comes to a stop?

Which one or more of the following pairs of displacements cannot be added to give a resultant displacement of 2 m?

A hole is drilled to the center of the earth and a ball is dropped into it.When the ball is at the earth's center, compared with their respective values at the earth's surface,

When its brakes are applied, a car moving at 10 m/s undergoes an acceleration of -1.2 m/s².In the next 5 s the car travels

Relative to what she weighs on the earth, an astronaut visiting another planet

The weight of an object is

The speed of an object moving in a circle is doubled.The centripetal force needed is

In the first 3 s after a car starts from rest with an acceleration of 4 m/s² it will travel

The Scientific Method

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The Nucleus

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Exam 2: Motion

According to Newton's third law of motion,

The sun exerts a gravitational force on the earth and the earth exerts a gravitational force on the sun.The force the earth exerts

A car starts from rest and reaches a speed of 15 m/s in 10s.Its acceleration is

The time needed for a car whose speed is 60 km/h to travel 800 m is

A 500-g ball moves in a circle 40 cm in radius at a speed of 4 m/s.The centripetal force on the ball is

A crane exerts an upward force of 200 N on a 20-kg crate.The crate's upward acceleration is

If the moon were half as far from the earth as it is now, the gravitational force it exerts on the earth would be

The escape speed needed for an object to leave the earth permanently

On a rainy day the maximum frictional force between a car's tires and a certain level road surface is reduced to half its usual value.The maximum safe speed for rounding a curve is

The mass of a 2,200-lb elephant is

The mass of a sack of potatoes whose weight is 200 N is

A snail travels 45 cm in 20 min.Its average speed is

When its brakes are applied, a car moving at 10 m/s undergoes an acceleration of -1.2 m/s2.How far does the car travel before it comes to a stop?

Which one or more of the following pairs of displacements cannot be added to give a resultant displacement of 2 m?

A hole is drilled to the center of the earth and a ball is dropped into it.When the ball is at the earth's center, compared with their respective values at the earth's surface,

When its brakes are applied, a car moving at 10 m/s undergoes an acceleration of -1.2 m/s2.In the next 5 s the car travels

Relative to what she weighs on the earth, an astronaut visiting another planet

The weight of an object is

The speed of an object moving in a circle is doubled.The centripetal force needed is

In the first 3 s after a car starts from rest with an acceleration of 4 m/s2 it will travel

The Scientific Method

Energy

Energy and the Future

Matter and Heat

Electricity and Magnetism

Waves

The Nucleus

The Atom

The Periodic Law

Crystals, Ions, and Solutions

Chemical Reactions

Organic Chemistry

Atmosphere and Hydrosphere

The Rock Cycle

The Evolving Earth

The Solar System

The Stars

The Universe

Filters

When its brakes are applied, a car moving at 10 m/s undergoes an acceleration of -1.2 m/s².How far does the car travel before it comes to a stop?

When its brakes are applied, a car moving at 10 m/s undergoes an acceleration of -1.2 m/s².In the next 5 s the car travels

In the first 3 s after a car starts from rest with an acceleration of 4 m/s² it will travel