Show:
Describing Forces
Net Force
Friction and Gravity
Types of Friction
100

What is a force?

A push or a pull

100

What is net force?

Net force is the sum of the forces acting on an object.

100

What is friction?

Friction is the force that two surfaces exert on each other when they rub together.

100

Name the four types of friction.

Sliding, static, fluid, rolling

200

What are the two qualities or ways of describing a force?

Strength and direction

200

In a game of tug of war, one group pulls to the left with 40 Newtons while one group pulls to the right with 60 Newtons. What is the net force on the rope and which direction will the rope travel?

The net force is 20 Newtons to the right.
200

What is gravity?

Gravity is a force that pulls objects towards each other.

200

What type of friction does an ice skater need to overcome in order to move forward?

Sliding friction

300

What unit is used to measure forces?

Newtons

300

Two people are moving a heavy cart. One person pushes to the right with 30 Newtons of force while the other person pulls to the right with 20 Newtons of force. What is the net force on the cart and in what direction will it travel.

50 Newtons to the right

300

What two factors affect the force of friction?

 The types of surfaces and how hard the surfaces are pushed together

300

What type of friction makes waterslides so fun?

Fluid friction

400

If an arrow is really long, what does that tell you about the force it is meant to represent?

The force is very strong.

400

Two children are arguing over a pencil. One child pulls the pencil towards himself with 10 Newtons of force while the other child pulls the pencil towards herself with 10 Newtons of force. Who will succeed in getting the pencil and why?

Neither child will succeed because the net force is zero and the pencil will not move.

400

What two factors affect the force of gravity between two objects?

The mass of the objects and the distance between them

400

A bunch of friends are trying to move a piano and are applying a lot of force to it but it still won't move. Using what you know about friction, what would you suggest they do?

Put the piano on wheels

500
A group of friends are moving a heavy piano. They exert 50 Newtons of force in the same direction but the piano will not move. What is happening to cause this lack of motion?

Friction is acting in the opposite direction with the same amount of force so the net force is zero.

500

What is the Law of Universal Gravitation?

The force of gravity acts between all objects in the universe that have mass.

500

What type of friction is the easiest to overcome?

Rolling friction