Science end of year revision

What are the different types of energy transfers?

Mechanical work : When a force is applied to an object through a distance, like pushing.

Thermal : Energy transfers from a hot object to a cold object.

Electrical work: A charge moving through a potential difference (e.g. current)

Radiation : Energy is transferred through the movement of light or sound waves.

How do you calculate ‘work done’

work done = force × distance

E=F×d

This is when:

• work done (E) is measured in joules (J)

• force (F) is measured in newtons (N)

• distance (d) is in the same direction as the force and is measured in metres (m)

What is a force?

A push or pull that can cause an object to accelerate, measured in newtons (N).

Name three contact forces

Friction, tension, normal (also known as the reaction force) and air Resistance

What is a contact force

A force that acts between objects in direct contact with each other, resulting in interactions such as pushing, pulling, or resisting motion.

Name non-contact forces

Forces that act at a distance without physical contact, including gravity, magnetism, and static electricity.

What is a balanced force?

When forces acting on an object are equal in size and opposite in directions, resulting in no change in motion.

If forces are balanced, what is the resultant force?

The resultant force will be 0

What is a physical quantity?

Something that can be measured.

What is tension?

A pulling force exerted by an object by a string, rope or rod.

What is friction?

A force that acts between two touching surfaces and prevents or resists them against each other. When two objects slide past each other they experience friction.

What is air resistance?

When an object moves through the air it experiences air resistance. This force acts against the direction the movement. The faster the object is travelling through the air - the greater the air resistance.

What is upthrust?

An upward force that acts on an object in a fluid.

Thrust

A driving force exerted by an engine to make an object move.