Energy changes in a system, and the ways energy is stored before and after such changes

Question 1

What is the energy change when you THROW AN OBJECT UPWARDS

Answer 1

When the ball leaves your hand, it has a store of kinetic energy.
By the time the ball reaches its highest point, it is now gravitational potential
Just before your catch the ball, it has a store of kinetic energy

Question 2

What is the energy change of A MOVING OBJECT HITTING AN OBSTACLE?

Answer 2

Just before the object hits the ground, it has a kinetic energy store
After it has hit the ground, it is thermal energy
The sound of the object dropping is dissipated to the surroundings

Question 3

What is the energy change ACCELERATING A CAR WITH A CONSTANT FORCE

Answer 3

There is a store of chemical energy in petrol.
As petrol burns, it transfers energy into kinetic energy store and thermal into the surroundings

Question 4

What energy changes are involved in heating a resistor?

Answer 4

Energy is transferred from the chemical store in the battery into the thermal store of the resistor and then into the thermal store of the surroundings

Question 5

What are examples of energy stores?

Answer 5

• Kinetic
• Chemical
• Gravitational
• Magnetic
• Elastic potential
• Electrostatic
• Thermal
• Nuclear

Question 6

What are the paths ways to transfer energy?

Answer 6

• Heating
• Work done by forces
• Work done when a current
• Electromagnetic radiation or mechanical radiation