science exam

A swimmer swims 20 m in 40 s. The swimmer's average speed is____m/s.

0.5

A student walks 20 m north, 10 m south, and 3 m north. To have a displacement of 0 m, the student should walk________m toward the_______.

Blank 1: 13 Blank 2: south

A coiled spring used to help a door close has_______ _______energy when the door is open.

Blank 1: elastic Blank 2: potential

Gravitational force differs based on two things. It increases with increasing_____It decreases with increasing_______.

Blank 1: mass Blank 2: distance

A fire warms you by transferring ____________________ energy.

Blank 1: thermal

A dump truck, a sports car, and a bicycle are traveling at the same velocity. Which is true? A) They all have the same kinetic energy. B) The sports car has the most kinetic energy. C) The bicycle has the least kinetic energy. D) More information is needed to compare their kinetic energy.

C) The bicycle has the least kinetic energy.

Which indicates what happens to the kinetic energy of an object when its speed increases? A) The kinetic energy does not change. B) The kinetic energy increases by the same factor as the speed increase. C) The kinetic energy increases by the square of the same factor as the speed increase. D) The kinetic energy decreases by the same factor as the speed increase. Correct Answer

C) The kinetic energy increases by the square of the same factor as the speed increase.

When two surfaces interact, some mechanical energy leaves the system as thermal energy due to ________. A) surrounding heat B) water C) friction D) fusion

C) friction

Which equation is correct? A) mechanical energy = kinetic energy - potential energy B) mechanical energy = potential energy - kinetic energy C) mechanical energy = kinetic energy + potential energy D) mechanical energy = kinetic energy × potential energy

C) mechanical energy = kinetic energy + potential energy

An object's weight is _____ its mass. A) equal to B) less than C) proportional to D) not related to

C) proportional to

Work _____ energy. A) reduces B) reflects C) transfers D) stops

C) transfers

In every energy transformation, some energy is always "lost" as ____ energy. A) chemical B) radiant C) electrical D) thermal

D) thermal

Knowing an object's position requires which of the following? A) speed B) time C) displacement D) reference point

D) reference point

A compressed spring does not have elastic potential energy.

False

A rock at the edge of a cliff has kinetic energy because of its position.

False

According to the law of conservation of energy, energy can be created or destroyed.

False

As a car slows down, its kinetic energy increases.

False

As mass decreases, kinetic energy increases.

False

Balanced forces acting on an object cause the object to accelerate.

False

Energy that is stored is kinetic energy.

False

Forces that are equal in size but opposite in direction are called unbalanced forces. _

False

If a net force acts on an object, the object may change speed, change direction or do neither.

False

If you throw a ball into the air, Earth exerts a force on the ball. The ball in the air exerts no force on Earth.

False

Mass varies depending on where the object is located. _______________

False

The law of__________of energy states that energy can be neither created nor destroyed, but it can change its form.

conservation

Which of the following is NOT true of gravitational force? A) noncontact B) depends on mass C) depends on speed D) distance

depends on speed

A stretched rubber band has what type of energy?

elastic potential energy

When coasting while roller skating, you eventually stop due to____.

friction

If an object is on top of a hill or in a position raised above the ground, it must have __________.

gravitational potential energy

When you move your hand or foot, your body has converted potential energy into______energy.

kinetic

Which type or types of energy does a blimp circling above a sporting event have?

kinetic energy and gravitational potential energy

The potential energy of an object depends on its______and its height.

mass

Differences in gravitational potential energy depend on an object's _________.

mass and height

The combined total of the kinetic and potential energy in a system is called _____.

mechanical energy

Kinetic energy is the energy of______

motion

Kinetic energy is the energy of_______.

motion

Acceleration depends on which two factors?

net force and mass

Friction always acts in a direction________to the direction of motion.

opposite

A kite stuck in a tree has ______ energy due to its position.

potential

Stored energy is called_____energy.

potential

The _____ can change when describing motion. It is just the chosen starting point.

reference point

Mass and weight are different. Mass depends on _____. Weight depends on _____.

the amount of matter, gravitational force

After braking, a bicycle's tires increase in temperature as friction causes some of the mechanical energy to transfer to________energy.

thermal

When there is friction between surfaces, energy is transferred out of a system as ________ energy.

thermal

Two people are pulling on a chain in opposite directions with forces of 500 N and 600 N. The forces would best be described as ____.

unbalanced forces

Which of the following is most closely related to gravity? A) distance B) mass C) weight D) speed

weight

Moving a book to a lower shelf decreases its potential energy.

True

The acceleration of an object is always in the direction of the net force acting on it. _______

True

When a bug hits a windshield of a car, the force of the car on the bug equals the force of the bug on the car.

True

When you push a pole downward on Earth to make a pole vault, Earth exerts an equal force on the pole.

True

When you put on the brakes of a bicycle, friction causes some of the mechanical energy to transfer to thermal energy.

True

Which has kinetic energy? A) a tank of gasoline B) a moving car C) a battery D) water in a reservoir

a moving car

According to Newton's second law of motion, a larger force acting on an object causes a greater __________of that object.

acceleration

When two objects interact through the gravitational force between them, the more massive one has a lower______than the less massive object.

acceleration

When two forces act in the same direction on an object, the net force is found by__________the forces.

adding

A ball has 100 J of potential energy when it is on a shelf. The kinetic energy of the ball the instant it hits the floor is_______J.

100

If you push on a wall with a force of 30 N, the force acting on you from the wall is which of the following?

30 N

A planet is discovered that has twice the mass of Earth but the same gravitational acceleration. If you weigh 700 N on Earth, on the new planet you would weigh ____.

700 N

Lizzie is pushing Alex on a scooter. Lizzie is pushing with 75 N of force to the left, and Alex is helping with 20 N to the left. What is the net force on the scooter?

95 N, to the left

Gravity is an example of which kind of force? A) contact B) noncontact C) speed D) direction

B) noncontact

Which would increase the kinetic energy of a wagon? Select all that apply. A) Add mass to the wagon. B) Decrease the mass of the wagon. C) Increase the speed of the wagon. D) Decrease the speed of the wagon.

A) Add mass to the wagon. C) Increase the speed of the wagon.

During a game of bowling, which of the following describe the ball's motion? A) The ball is accelerated while it is pushed by the student's hand due to an unbalanced force. B) The ball slows down as it rolls because friction exerts an unbalanced force. C) The ball is accelerated while it is held in the student's hand due to balanced forces. D) The ball does not change its motion as it rolls because of the balanced force provided by friction. E) The ball does not change its motion while it is held in the student's hand due to balanced forces.

A) The ball is accelerated while it is pushed by the student's hand due to an unbalanced force. B) The ball slows down as it rolls because friction exerts an unbalanced force. E) The ball does not change its motion while it is held in the student's hand due to balanced forces.

If the mass of one of two spheres increases, how does it affect the gravity between the two spheres? A) The gravity increases. B) The gravity decreases. C) The gravity fluctuates. D) The gravity is not affected.

A) The gravity increases.

Which type of energy does an object not have if it is not moving? A) kinetic energy B) gravitational potential energy C) elastic potential energy D) chemical potential energy

A) kinetic energy

According to the law of conservation of energy, the total amount of energy in the universe ____. A) remains constant B) changes constantly C) increases D) decreases

A) remains constant

There is a gravitational force between you and your desk. This gravitational force is very small because _____. A) the masses are tiny compared to Earth's mass B) it doesn't need to be large C) the distance between the objects is small D) it is a noncontact force

A) the masses are tiny compared to Earth's mass

Which best describes the changes in energy as a child goes down a slide? A) potential energy decreases and kinetic energy increases B) potential energy is constant and kinetic energy increases C) potential and kinetic energy are constant D) mechanical energy decreases

A) potential energy decreases and kinetic energy increases

Pick the best example of Newton's third law of motion in action. A) A rocket accelerating in space as a result of gases and the rocket pushing each other in opposite directions. B) A rocket being towed to the launch pad while friction acts in the opposite direction. C) An asteroid moving around the Sun while being pulled toward the Sun. D) An asteroid continuing to spin because nothing has exerted a force to stop it.

A) rocket accelerating in space as a result of gases and the rocket pushing each other in opposite directions.

Kelly sits on a rock in a field. Which of the following correctly name force pairs? A) Kelly pushes on the rock, and the rock pushes on Earth. B) Earth pulls on Kelly, and Kelly pulls on Earth. C) The rock pushes on Earth, and Earth pulls on the rock. D) Kelly pushes on the rock, and the rock pushes on Kelly.

B) Earth pulls on Kelly, and Kelly pulls on Earth. D) Kelly pushes on the rock, and the rock pushes on Kelly.

Which indicates what happens to the kinetic energy when the mass of a moving object increases? A) The kinetic energy does not change. B) The kinetic energy increases by the same factor as the mass increase. C) The kinetic energy increases by the square of the same factor as the mass increase. D) The kinetic energy decreases by the same factor as the mass increase.

B) The kinetic energy increases by the same factor as the mass increase.

Which of the following does NOT reduce friction? A) grease B) cotton C) oil D) graphite

B) cotton

The statement "for every action, there is an equal but opposite reaction" is a statement of ____.

Newton's third law

A test booklet is sitting at rest on a desk. Compared to the force of the booklet on the desk, the force of the desk on the booklet is the same. _______________

True

Based on Newton's third law of motion, when a person on a skateboard throws a heavy concrete block to the north, the person will be pushed to the______.

South