Elastic, Chemical, and Gravitational Energy

Energy

0625 Physics

Learning Objective 1

• Identify changes in kinetic, gravitational potential, chemical, elastic (strain), nuclear and internal energy that have occurred as a result of an event or process.

Multiple Choice

Every moving object has energy in this energy store

• Kinetic

• Elastic

• Chemical

• Nuclear

Multiple Choice

Two magnets close together have energy in this energy store.

• Chemical

• Elastic

• Magnetic

• Gravitational Potential

Multiple Choice

Two negatively charged particles which are close together have energy in this energy store

• Electrostatic

• Magnetic

• Nuclear

• Elastic

Multiple Choice

A stretched rubber band has energy in this energy store

• Magnetic

• Electrostatic

• Elastic

• Nuclear

Multiple Choice

Food, fuels and batteries have energy in this energy store

• Chemical

• Thermal

• Gravitational Potential

• Elastic

Multiple Choice

A roller coaster at the top of a hill has energy in this energy store.

• Gravitational Potential

• Thermal

• Elastic Potential

• Chemical

Learning Objective 2

• Recognise that energy is transferred during events and processes, including examples of transfer by forces (mechanical working), by electrical currents (electrical working), by heating and by waves

Multiple Choice

Energy which is transferred due to temperature difference caused electrically or by a chemical reaction.

• Mechanically

• Electrically

• By Radiation

• By Heating

Multiple Choice

Energy which is transferred by a force moving an object through a distance

• Mechanically

• Electrically

• By Radiation

• By Heating

Multiple Choice

Energy which is transferred by charges moving due to a potential difference (voltage)

• Mechanically

• Electrically

• By Radiation

• By Heating

Multiple Choice

Energy which is transferred as a wave, for example light.

• Mechanically

• Electrically

• By Radiation

• By Heating

Learning Objective 3

• Recall and use the expressions kinetic energy = ½mv 2 and change in gravitational potential energy = mg∆h

Gravitational Potential Energy

mass x gravitational field strength x height

Kinetic Energy

 $\frac{1}{2}$  x mass x  $Speed^2$  

Multiple Choice

An Olympic high jumper, with a mass of 82 kg, has a maximum gravitational potential energy of 1970 J. How high was the jump?

Let g = 9.8N/kg

• 24 m

• 161,540 m

• 2.5 m

• 201 m

Multiple Choice

How could you increase the gravitational potential energy of an object without changing its mass and gravity?

• Make the object larger

• Lower the object towards the ground

• Raise the object farther off the ground

• Allow the object to roll on the ground

Multiple Choice

At which point does the ball has the greatest gravitational potential energy (GPE)?

• A

• G

• D

• C

• G

Multiple Choice

What is the mass of a moving object that has 100 Joules of KE and moves at a velocity of 2 m/s?

• 50 kg

• 200 kg

• 25 kg

• 100 kg

Multiple Choice

What two factors affect an object's kinetic energy?

• area and volume

• mass and weight

• weight and height

• mass and speed

Learning Objectives 4

• Apply the principle of conservation of energy to simple examples

• Apply the principle of conservation of energy to examples involving multiple stages

• Explain that in any event or process the energy tends to become more spread out among the objects and surroundings (dissipated)

Energy transferred as the skier rade down the hill

GPE to KE

Skier in a downhill race

Energy Lost= Energy Gained 

mgh=  $\frac{1}{2}$   $mv^2$  

Assuming no energy is dissipated as heat or sound energy

Multiple Choice

What does the Law of Conservation of Energy state?

• Energy cannot be created or destroyed

• Nothing can exchange energy

• Energy will increase over time.

• Energy will decrease over time.

Multiple Choice

A 40 kg crate is picked up by a crane to a height of 50m. The crate falls. What is the velocity of the crate just before it hits the ground?

• 2000 Joules

• 19,600 Joules

• 19,600 m/s

• 31.3 m/s