Physics

What is a force?

A force is any push or pull that happens when two objects interact.

What is a simple push or pull called

An applied force

What is an applied force

A simple push or pull

What are contact forces?

Forces that act when two objects are touching

What is a non-contact force?

When two objects do not need to be touching for a force to act

What can forces do?

They can change shape, speed or direction

How are forces measured?

They are measured in Newtons

What are two thing you can use to measure forces with?

A spring balance or scales

How do you describe the force at work in this image.

The leg is pushing the ball. This is causing the ball the change speed and direction.

What is a force diagram?

a diagram that shows all the forces acting on an object

What is an unbalanced force?

When the net force on an object is not 0N and can change speed, direction or shape

What are balanced forces?

When the net force on an object is exactly 0N and does not change speed, direction or shape.

Describe the net force in this image

The force is unbalanced and the net force is 400 N to the ground.

What is friction?

Friction is a contact force that resists movement between two objects.

What are two factors that affect the amount of friction?

The weight of the object being pushed or pulled and the smoothness of the surface.

What are four ways to reduce friction?

Lubrication, rollers or balls, levitation and streamlining.

Explain lubrication

It is when you use a lubricant such as oil or grease which reduces friction by making the surface slippery.

Explain Rollers or Balls

It is when a roller or ball rolls along surfaces because it produces less friction than sliding because of less contact.

Explain levitation

It is when you reduce or remove contact between two surfaces.

Explain Streamlining

It is when you make an object smooth and round to reduce friction between and object and air(or water.)

What is mass?

Mass is the amount of matter in an object and it is the same in every planet.

What is mass measured in?

kg

What is weight?

It is the force of a planet's pull on an object. It change in other plantets

What is weight measured in?

Newtons

What is gravity?

It is a force that pulls objects with mass together.

What does the strength of gravity depend on?

The object's mass and distance

What are atoms made of?

electrons, protons, neutrons

What are electrons?

they are negatively charged particles

What are protons?

They are positively charged particles

What are neutrons?

They are particles with no charge.

What are neutrons attracted to?

They are attracted to charge objects.

What is a magnet

A magnet is something that produces a magnetic field

What are magnets made up of?

They are made up of smaller magnetic parts called magnetic domains.

What are three materials that contain magnetic domains?

Iron, nickel and cobalt.

What is lever?

A lever is a rod or bar that is supported at a turning point called a fulcrum.

What does a lever do?

A lever takes an input force and creates an output force

What is the input force?

The input force is the force used to operate a lever (effort)

What is the output force?

The output force is the force that the lever creates.

What is mechanical advantage?

The mechanical advantage is how much easier it is to lift an object.

What are class 1 levers?

Class 1 levers are levers with the fulcrum in the middle

What is the fulcrum?

It is the turning point of a lever

What are class 2 levers

Class 2 levers are levers with the output force in the middle.

What are class 3 levers?

Class 3 levers are levers with the input force in the middle

What is a pulley?

It is a wheel with a groove and has a rope in the groove. It is a simple machine

What does a pulley do?

A pulley can change the direction of force and also create a mechanical advantage.

How do you create a mechanical advantage with pulleys.

To create a mechanical advantage, you need two or more pulleys together which creates a pulley system.

What does the distance you have the rope depend on?

It multiplies by the number of pulleys.