10.1- WORK AND ENERGY

Question 1

What is energy needed to do to a stationary object? (3)

Answer 1

energy needed to make stationary objects move, to change their shape, or to warm them up

Question 2

When you lift an object up where do you transfer energy from and where to?

Answer 2

transfer energy from muscles to object

Question 3

Examples of energy in different types of stores that objects can possess? (4)

Answer 3

gravitational potential stores
kinetic stores
thermal stores
elastic stores

Question 4

What is gravitational stores of energy?

Answer 4

position of object in gravitational field

Question 5

What objects have energy in kinetic store?

Answer 5

moving objects

Question 6

What objects have energy in thermal store?

Answer 6

hot objects

Question 7

What objects have energy in elastic store?

Answer 7

objects compressed or stretched

Question 8

Examples of ways that energy can be transferred between objects? (3)

Answer 8

radiation (e.g. light)
electrically
mechanically (e.g. sound)

Question 9

What is energy measured in?

Answer 9

joules (J)

Question 10

What is one joule equal to?

Answer 10

energy needed to raise a 1N weigh through vertical height of 1m

Question 11

What does the principle of conservation of energy state?

Answer 11

energy cannot be created or destroyed

Question 12

When is work done on an object?

Answer 12

when force acting on it makes it move

Question 13

When work is done on an object, what is transferred?

Answer 13

energy transferred to object

Question 14

What does the amount of work done on an object depend on?

Answer 14

depends on force + distance object moved

Question 15

What happens to work done, the greater the force or further the distance?

Answer 15

greater the work done

Question 16

What is the equation for work done?

Answer 16

work done = force * distance moved in direction of force

Question 17

What is the unit of work done?

Answer 17

joule (J)

Question 18

Imagine a yacht acted on by a wind force F at an angle θ to the direction in which the yacht’s moving. What is the component of the wind force in the direction of motion of the yacht?

Answer 18

Fcosθ

Question 19

Imagine a yacht acted on by a wind force F at an angle θ to the direction in which the yacht’s moving. What is the component of the wind force at right angle to direction of motion of the yacht?

Answer 19

Fsinθ

Question 20

What does the area under a force-distance graph represent?

Answer 20

work done

Question 21

What is the equation to stretch spring to extension ΔL?

Answer 21

work done = 1/2FΔL