Year 8 Science Energy and Pressure

Question 1

What’s the formula for the efficiency of energy transfer?

Answer 1

The efficiency of energy transfer = Useful power output/Total power output x 100

Question 2

What are the units used for Thermal Energy?

Answer 2

Joules J measures the amount of Energy.

Question 3

Fill the gap: The more _ the more Thermal Energy

Answer 3

The more particles an object has the thermal energy it has.

Question 4

What are the three ways of the transfer of Thermal Energy?

Answer 4

Convection, Conduction, and Radiation
Convection is when a liquid is heated causing the particles to have more energy, losing density so rise and then cool, and the current continues…
Conduction is when particles are heated and gain energy. As they move they pass the heat to the next particle.

Question 5

What’s the formula for Power?

Answer 5

Power Transfer = Energy ÷ Time.

Question 6

What’s the energy transfer for a log burner using 20W for 60 seconds?

Answer 6

1200J is the energy used.

Question 7

What’s the formula for force?

Answer 7

Mass (kg) x acceleration (m/s^2)

Question 8

What’s the formula for pressure?

Answer 8

Force/ Area (m^2)