FWE

Question 1

What is the Principle of Conservation of Energy

Answer 1

Energy cannot be created or destroyed but can be converted from one form to another or transferred from one object to another

Question 2

When a ball rebounds, why is it unable to reach its original position [3]

Answer 2

Some energy has been transferred to the surroundings as heat and sound when it hits the floor
EPE<GPE at original position
EPE converted to KE + GPE when ball bounces up. GPE at max. height of ball< total energy before

Question 3

Name 4 properties of a force

Answer 3

• Either a push or pull that exerts on another object
• Has both magnitude and direction
• Can cause a turning effect in objects and exert pressure on objects
• Can change shape, size, direction of motion or speed

Question 4

What is chemical potential energy

Answer 4

Energy stored in fuels such as petrol and food that can be released through chemical reactions

Question 5

How to calculate work done

Answer 5

Work done (J) = Force (N) x distance moved in the direction of the force (m)

Question 6

What is energy

Answer 6

The capacity to do work

Question 7

Define potential energy

Answer 7

Stored energy due to the body’s position or condition

Question 8

Define pressure

Answer 8

Amount of force acting perpendicularly on a unit of area

Question 9

Define elastic potential energy

Answer 9

Amount of energy stored in an object that is stretched or compressed

Question 10

Define work done

Answer 10

The conversion of energy when energy is transferred between objects or converted from one form to another

Question 11

What is gravitational potential energy

Answer 11

The amount of energy an object has based on its position or location

Question 12

How does energy overcome friction/air resistance

Answer 12

Converted to thermal and sound energy

Question 13

What is kinetic energy

Answer 13

Energy that a body has due to its motion

Question 14

What does heat refer to

Answer 14

Flow of thermal energy

Question 15

What is electrical energy

Answer 15

Energy transferred by the flow of charged particles

Question 16

How is sound produced

Answer 16

When objects vibrate and it is transmitted through a material

Question 17

What is an elastic force

Answer 17

Force that is acting on a stretched or compressed object to return it to its original shape, in the opposite direction of the force exerted

Question 18

What is frictional force

Answer 18

Force exerted that opposes or tends to oppose the motion between surfaces in contact

Question 19

What is gravitational field strength

Answer 19

The gravitational force acting on a unit mass of an object

Question 20

What are electrostatic forces

Answer 20

The forces acting between two charged particles

Question 21

If the speed and direction of the object does not change, can we conclude that there are no forces acting on it

Answer 21

No. We can only conclude that there is no resultant/net force acting on it

Question 22

What is the force exerted by Earth’s atmosphere called

Answer 22

Atmospheric pressure

Question 23

What are the three criteria for work to be done

Answer 23

• Force must be applied on object
• Object must move
• Object must move in direction of the force applied

Question 24

What are the three components of work done

Answer 24

• Change in GPE
• Change in KE
• Energy converted to thermal and sound energy/work done against friction or air resistance