Year 8 term 2 2026 science test 1

What is the scientific definition of energy?

The ability of an object to make a change.

What are the three core rules of how energy behaves?

1. Energy cannot be created or destroyed. 2. Energy can be transferred from one object to another. 3. Energy can transform into another type of energy.

What is the purpose of an energy flow diagram?

They show a simplified presentation of how energy is transformed or transferred.

What is the standard scientific unit used to measure energy?

Joules (or J for short).

What are the 5 main types of Potential (Stored) Energy?

1. Elastic Energy, 2. Gravitational Energy, 3. Electrical Energy, 4. Chemical Energy, 5. Nuclear Energy.

What are the 5 main types of Kinetic (Movement) Energy?

1. Heat Energy, 2. Light Energy, 3. Sound Energy, 4. Electrical Energy, 5. Kinetic Energy.

What is the formula to calculate Gravitational Potential Energy (Ep)?

Mass x Weight x Height = Ep

What is the formula to calculate Kinetic Energy (Ek)?

1/2 x Mass x Velocity = Ek

What is the formula to calculate Density?

Density = Mass of object / Volume of object

What are the two ways we can measure the energy contained in food?

1. Check the back of box nutrition info. 2. Burn food and measure the temperature change.

In an Energy Skate Park, if the person returns to the same height on a frictionless track, is energy conserved?

Yes, the energy is conserved.

How is energy conservation observed as a skater moves down and up a track?

Heading down the track, potential energy is transformed into kinetic energy. Heading up the track, kinetic energy is transformed into potential energy.

What happens if there is friction on the skate track?

The friction slows down the skater, and kinetic energy is transformed into heat energy.

Is energy still conserved when friction is present on the track?

Yes, the total energy stays the same. The heat energy is just not useful, meaning it has been 'lost' from the motion.

What is the basic energy flow diagram for a falling object?

Gravitational Ep -> Kinetic Energy

Are all energy outputs from an object useful?

No, only some of the energy you get out is useful.

What is the definition of Energy Efficiency?

The percentage of the useful energy compared to the original input energy.

What is the formula to calculate Energy Efficiency (E.E.)?

E.E. = (Useful Energy / Input Energy) x 100%

When do atoms vibrate more?

When the temperature is higher.

What is Conduction and which state of matter does it work best in?

A hotter atom collides with a colder atom, passing on heat energy. Solids conduct best when the atoms are closest.

What is Convection and how does density affect it?

Hotter fluid/water is less dense so it rises, while colder fluid/water is denser so it sinks.