P1 Energy

Question 1

Name all the 8 energy stores.

Answer 1

Chemical, Nuclear, Elastic, Thermal, Kinetic, Magnetic, Gravitational Potential, Electrostatic

Question 2

What is gravitational potential energy?

Answer 2

Energy stored in an object due to its height above the ground.

Question 3

What is elastic potential energy?

Answer 3

Energy stored when an object is stretched or compressed, like a spring.

Question 4

What is chemical energy?

Answer 4

Energy stored in chemical bonds, such as in food, fuels, or batteries.

Question 5

What is kinetic energy?

Answer 5

Energy an object has due to its motion.

Question 6

What is nuclear energy?

Answer 6

Energy stored in the nucleus of an atom, released during nuclear reactions.

Question 7

What happens to energy in a closed system?

Answer 7

Energy is conserved; it cannot be created or destroyed, only transferred or transformed.

Question 8

What is the equation for kinetic energy?

Answer 8

Kinetic Energy (J) = 0.5 × mass (kg) × velocity² (m/s²).

Question 9

What is the equation for gravitational potential energy?

Answer 9

Gravitational Potential Energy (J) = mass (kg) × gravitational field strength (N/kg) × height (m).

Question 10

What happens to energy in a system when a car accelerates?

Answer 10

Chemical energy in the fuel is converted into kinetic energy.

Question 11

How is energy transferred in a mechanical system?

Answer 11

Through forces doing work, causing energy to be transferred from one store to another.

Question 12

What is the relationship between work done and energy transfer?

Answer 12

Work done is the transfer of energy from one store to another.

Question 13

What is power in terms of energy transfer?

Answer 13

Power is the rate at which energy is transferred or work is done.

Question 14

What is the unit of power?

Answer 14

The watt (W), where 1 watt equals 1 joule per second (J/s).

Question 15

What is Specific Heat Capacity?

Answer 15

The specific heat capacity of a substance is the amount of energy required to raise the temperature of 1kg of the substance by 1°C.

Question 16

How do you calculate specific heat capacity?

Answer 16

specific heat capacity (J/kg°C) = change in energy (J) / mass (kg) x temperature change (°C)
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Question 17

How do we calculate efficiency?

Answer 17

Useful output energy transfer / Total input energy transfer

Question 18

What is efficiency?

Answer 18

Efficiency is the ratio of useful energy output to total energy input, usually expressed as a percentage.

Question 19

Suggest a method to determine the specific heat capacity of oil.

Answer 19

Set up the apparatus: Pour a known mass of oil into a beaker. Place the beaker in an insulated container (e.g., a calorimeter) with insulating foam around it to minimize heat loss.

Insert a thermometer and heater: Place a thermometer into the oil to measure temperature and insert a known-power electric heater into the oil.

Measure the initial temperature: Record the initial temperature of the oil before turning on the heater.

Switch on the heater: Turn on the heater and allow it to heat the oil for a set period, typically around 30 minutes, while making sure the heater is submerged in the oil.

Measure the final temperature: After 30 minutes, record the final temperature of the oil using the thermometer.

Calculate the specific heat capacity. Using change in energy / mass x change in temperature

Question 20

What are possible inaccuracies of the specific heat capacity practical?

Answer 20

• Not all thermal energy is going into the beaker (Fully submerge the heater)
• Incorrectly reading the thermometer (Use electronic temperature probe.)
• Thermal energy may not be spread (Stir the oil.)