Force, Gravity

Question 1

The force that resists the movement of one surface past another is called ————

Answer 1

Friction

Question 2

A push or pull is called a ——

Answer 2

Force

Question 3

Two magnets that are held together are an example of a force that (does, or does not) touch

Answer 3

Does not

Question 4

The speed of a moving object can be changed by (balanced, unbalanced) forces.

Answer 4

Unbalanced

Question 5

The sum of all forces acting on an object is called (balanced, net) force.

Answer 5

Net

Question 6

Friction is mainly caused by (rough, smooth) surfaces.

Answer 6

Rough

Question 7

The type of friction that acts on moving bicycle wheels is called (rolling, sliding) friction.

Answer 7

Rolling

Question 8

Soil erosion by wind is an example of (helpful, harmful) friction.

Answer 8

Harmful

Question 9

What’s the difference between balanced and unbalanced forces?

Answer 9

Balanced forces do not cause a change in motion. They are equal in size and opposite in direction.
Unbalanced forces always cause a change in motion. They are not equal and opposite

Question 10

What is an example of a balanced force?

Answer 10

Two cards leaning against each other and not falling over

Question 11

What is an example of an unbalanced force?

Answer 11

Falling from the bed, or a book falling from a table

Question 12

Explain what forces are acting on a book that you are holding steady in the palm of your hand.
Then tell whether the forces are balanced or unbalanced.

Answer 12

Gravity, a balanced force

Question 13

Describe how force and mass worked together to create motion for your vehicle.

Answer 13

Used a falling weight system to make the car go. The falling weight system where the force of gravity is pulling on the mass, making the vehicle move.

Question 14

How did you use friction to help move your vehicle?

Answer 14

Used friction from the rubber band to turn the rear axle which made the vehicle move forward.

Question 15

How did friction work against the movement of your vehicle?

Answer 15

The friction was going the opposite direction of the vehicle making the vehicle slow down

Question 16

What is friction?

Answer 16

The force that resists the movement of one surface past another

Question 17

List the 4 types of friction and an explanation of each.

Answer 17

Static-resists the motion of an object just as it begins to move
Rolling-resists the motion of a rolling object
Sliding-resists the motion of a sliding object
Air resistance-something that pushes by air

Question 18

Name and describe the laws of motion.

Answer 18

First law-The law of inertia-an object at rest stays at rest, an object in motion stays in motion, unless acted upon by an unbalanced force
Second law-the acceleration of an object depends on the mass of object and the size of the net force applied
Third law-when a force is applied to an object, the object exerts an equal force in the opposite direction

Question 19

What is speed?

Answer 19

A measure of how fast an object is moving

Question 20

What is velocity?

Answer 20

The speed of an object in a particular direction

Question 21

Give an example of the first law of motion.

Answer 21

A bowling ball will keep rolling until gravity and friction stops it.

Question 22

Give an example of the second law of motion.

Answer 22

Pushing a ball

Question 23

Give an example of the third law of motion.

Answer 23

When a rocket goes off the pad, the exhaust in the back pushes the rocket to go the opposite direction

Question 24

Why is the first law of motion called the Law of Inertia?

Answer 24

Inertia means the tendency of an object to remain at rest or in constant motion unless a force acts upon it

Question 25

How are weight and gravity related?

Answer 25

Weight is the effect caused by gravity. If gravity increases, so does weight.

Question 26

What is acceleration?

Answer 26

The rate at which the velocity of a body changes with time

Question 27

How can friction help people at sports?

Answer 27

In basketball, it allows people to change directions quickly. The friction between their shoe and the floor lets them slow down sufficiently.

Question 28

What is gravity?

Answer 28

The force that attracts a body toward the center of the earth, or toward any other physical body having mass

Question 29

What are effects of gravity on the earth and moon?

Answer 29

On earth, gravity keeps the air and everything around us from drifting off into space. It causes things to fall to the ground, and causes the ocean’s tides, causes hot air to rise and colder air to fall (causing wind)

On the moon, the force of gravity is much less. People would weigh much less on the moon, because the moon is smaller and there is less gravitational pull. And you could jump a lot higher on the moon than on earth.

Question 30

The moon’s gravity is about (what fraction) of the gravity on earth?

Answer 30

About one-sixth

Question 31

The amount of gravitational force depends on what?

Answer 31

The distance between two objects—the greater the distance, the less gravitational pull it has.
And, the mass of the two objects—the greater the mass, the stronger the gravitational pull

Question 32

Which has more gravitational pull, Earth or the moon? Why?

Answer 32

The earth, because it has a larger mass than the moon

Question 33

In what unit are forces measured?

Answer 33

Newtons

Question 34

What is used to find the force needed to stop a moving object?

Answer 34

Momentum- the more momentum it has, the harder it is to stop

Question 35

What is mass?

Answer 35

How heavy something is without gravity–the amount of matter an object has