Phisics QQQ

Lesson

Question

Answers

1.1

Name three stores of energy?

Chemical, Kinetic, Gravitational Potential, Elastic Potential, Thermal Energy, Magnetic,

Eloctrostatic

11

Name 2 types of energy that is wasted in a car?

Thermal, chemical

1.1

Describe the energy transfer when bungee Jumping?

Kinetic to elastic potential to kinetic

1.1

What is energy measured in, In terms of unit?

Joules (i)

1.2

What does conservation of energy mean?

Energy cannot be created or destroyed only transferred

1.2

On a pendulum at what point would the maximum kinetic energy be present?

at the lowest point (pendulum is straight)

1.2

What is a closed system?

Energy cannot enter or leave the system

1.3

What is the formula for work done?

Work done = force x distance

1.3

What force does a brake pad use in order to slow down the car?

Friction between pad and tyre

1.3

Name the contact force that causes an object to slow down?

Friction

1.3

When is Work done?

When an object is moved by a force.

1.4

How can you calculate change of gravitational potential energy?

Change GPE = mass x

Gravitational Field Strength x change in height

1.4

What is the definition for gravitational potential energy?

The potential energy an object dependant on its mass, the planet it is on (Its GFS) and its height from the ground.

1,4

Name one way to decrease the gravitational potential energy of an object?

Lower or drop it

1.5

What is the formula used to calculate elastic potential energy?

EPE = / x spring constant x

extension?

1.5

What law can a ferce extension graph show?

Hooke's law


1.5

What is the formula for Kinetic energy>

1.6

What does energy dissipation mean?

KE =½ x mass x velocity?


Energy that dissipates

spreads out and becomes less useful




1.6

1.6

What does the term useful energy mean?

What does the term wasted energy mean?

Energy transferred to where it is wanted to do the job that is wanted

Is the energy that is not usefully transferred.

1.7

If the useful energy is 250J and the total energy is

2000J what is the efficiency?

250/2000 = 0.125

X 100 = 12.5%

1.7

Name two examples of how you could improve efficiency?

Increase useful energy output

Decrease total energy output

1.7

What does the term efficiency limit mean?

This is the maximum amount of energy transferred to useful energy within a closed system

1.7

What is the formula used to calculate efficiency?

Efficiency = useful energy / total energy(x100 for percent)




1.8

What is the useful energy in a kettle?

Thermal

1,8

What is the wasted energy in a car engine?

Thermal, energy transferred as sound waves

1.8

What is the useful energy in a TV?

Energy transferred as sound and light waves

1.9

What is power measured in, in terms of units?


Watts (w)

1.9

What is power?

The amount of energy supplied per second

1.9

What is the equation to calculate power?


Power (in watts) = Energy

transferred to appliance (in joules) / time taken for the energy to be transferred(in seconds)