Section 17 - Motion, forces and conservation of energy - Energy stores, transfers, efficiency and resources

Question 1

Name the 8 energy stores?

Answer 1

Kinetic, thermal, chemical, gravitational potential, elastic potential, electrostatic, magnetic, nuclear

Question 2

Equation for kinetic energy?

Answer 2

Kinetic energy (J) = 0.5 x mass (kg) x speed² (m/s)²
KE = 0.5 x m x v²

Question 3

Equation for gravitational potential energy?

Answer 3

Change in gravitational potential energy (J) = mass (kg) x gravitational field strength (N/kg) x change in height (m)
∆GPE = m x g x ∆h

Question 4

What is the conservation of energy?

Answer 4

Energy cannot be created or destroyed. The total energy of a closed system has no net change

Question 5

Four main ways energy can be transferred between stores?

Answer 5

Mechanically, electrically, by heating or by radiation

Question 6

Equation for efficiency?

Answer 6

Efficiency = useful energy ÷ total energy

Question 7

Main way energy is dissipated or wasted?

Answer 7

Thermal energy stores or heating of the surroundings

Question 8

Two ways to reduce the amount of energy that is wasted during a process?

Answer 8

Lubrication and insulation

Question 9

Difference between renewable and non-renewable energy resources?

Answer 9

Renewable will never run out, non-renewable will run out

Question 10

2 examples of non-renewable energy resources?

Answer 10

Nuclear power and fossil fuels

Question 11

2 environmental problems caused by burning fossil fuels?

Answer 11

Release CO2 into atmosphere when burned, which adds to greenhouse effect and contributes to global warming
Release sulfur dioxide which causes acid rain

Question 12

6 examples of renewable energy resources?

Answer 12

Bio-fuels, wind, solar, hydro-electric, tides, geothermal