7th Grade Forces

Forces

100

A force is defined as this

Push or a Pull

200

Force is measured in this

Newtons

300

Magnetic force is what type of force?

Non-contact force

400

Give at least 2 types of non-contact forces or contact forces

Magnetic, Electrostatic, Gravity

or

buoyancy, friction

500

Quinn pushes a box to the right with 5 N and Shandelle helps push to the right also with 7 N. This is the net force

12 Newtons

Friction

100

This occurs when two object rub against each other

Friction

200

List three ways in which friction can be reduced. Give an example of each method.

• using lubricants — for example, in car engines where oil is used to lubricate between the moving pistons and engine block
• polishing surfaces, reducing the traction between the two surfaces — for example, sharpening the blades of ice-skates 
• using ball bearings — this allows relative motion between two surfaces, such as the axle and wheel hub of a skateboard.

300

Are wider tyres better than narrow ones?

Wider tyres create more friction; however, they consume more fuel. Narrow tyres create less friction but consume less fuel. There is no objectively better type; preference will depend on the situation for which they are being used.

400

This type of friction occurs when birds fly in the air

Fluid Friction

500

The two factors that affect friction

Surface and Force

Random

100

What's heavier? 1000 kg of feathers or 1000 kg or iron?

They're the same weight having the same mass.

200

If you were to land on Mars, what would change?

A) Your mass

B) Your weight

C) Both your mass and your weight

D) Neither your mass or your weight

Weight

300

How does it affect your driving when the tread is worn away and the tyres are ‘bald’?

When the tread is worn, less friction is created, making it more difficult to control the car around tight bends or in wet weather.

400

Name the three forces acting on a water spider when it is standing on a still pond.

Gravity, buoyancy and surface tension.

500

If every object pulls on other objects with a force of gravity, explain why you don’t notice objects being attracted to you.

You do attract other objects, it is just that the force of attraction is so small that the effects in isolation would be minimal, and other forces such as friction dominate.

Misc

100

Force that pulls objects towards each other

Gravity

200

The amount of matter in an object

Mass

300

The measure of the force of gravity on an object

Weight

400

These two things affect gravitational pull

Mass and Distance

500

Explain why small & light objects such as leaves or insects do not sink when on the surface of water

The water is held in shape by surface tension. Surface tension is the pulling of particles in a liquid towards each other.

Soaps and detergents reduce the surface tension of water.

Gravity

100

What keeps the Moon in orbit around the Earth and the planets in orbit around the sun?

Gravity

200

Every object in the universe pulls on other objects with a force of gravity. True or false?

True

300

What does affect the force of gravity?
A) Weight
B) Place
C) Size
D) Mass

The force of gravity towards an object depends on its mass

400

Air in the atmosphere pushes against all falling objects. This push force is called what?
Or: what is this an example of?

Air resistance

Fluid friction

500

Explain the difference between mass and weight

Mass is the amount of matter in an object, while weight is the force of gravity on it. 

That's why astronauts make big leaps with every step, because they weigh less without having lost any mass. The Moon has smaller gravitational pull because its mass is smaller than Earth's.