Dedicated to My Son Mohammad Irtaza Zain. Code 5054

[Total 19 Marks]

Date :................................ Code: 5054 Class: CI

Test (Unit 6)

[Total 6]

UNIQUE SCIENCE ACADEMY

Name :............................................................................... Paper: Physics

Time Allowed: 35Minutes Maximum Marks: 25

1

Theory Section:

[Turn over

Fig. 1.1

Fig. 1.1 shows part of a small hydroelectric system that generates electricity from moving water.1 generator

turbine

waterpipe

(a) Every minute, water with kinetic energy 14 000 J emerges from the pipe. The water turns a turbine that is connected to the generator.

Half of the kinetic energy of the water is given to the generator. (i) Calculate the power input to the generator.

power = .......................................................... [3]

(ii) Suggest a reason why only some of the kinetic energy of the water is given to the generator.

...........................................................................................................................................

...................................................................................................................................... [1]

(b) Hydroelectric systems use sources of renewable energy. (i) State what is meant by renewable energy.

...........................................................................................................................................

...................................................................................................................................... [1]

(ii) State one source of non-renewable energy.

...................................................................................................................................... [1]

[Total 7]

2

Dedicated to My Son Mohammad Irtaza Zain. Code 5054 [Turn over

2 Fig. 2.1 shows a motor used to operate a lift (elevator). There is a man in the lift.

motor

lift

cable

Fig. 2.1 (not to scale)

The input power to the motor is 6200 watts. (a) Define the watt.

..........................................................................................................................................

...................................................................................................................................... [2]

(b) The lift and the man have a total mass of 580 kg. The lift moves up a distance of 12 m in 15 s.

(i) Calculate the tension in the cable when the lift is moving at constant speed.

tension = ................................ [1]

(ii) Calculate the increase in potential energy of the lift and man.

potential energy = ................................ [2]

(iii) Calculate the efficiency of the motor.

efficiency = ................................ [2]

3

Dedicated to My Son Mohammad Irtaza Zain. Code 5054[Total 6]

[Turn over

Fig. 3.1

Fig. 3.1 illustrates the journey of a cyclist from point A to point B. Points A and B are at the same 3 height.

A B

The cyclist starts from rest at A and pedals up and over a hill. Near the bottom of the hill, she starts to brake and comes to rest at B.

(a) Describe the energy changes that take place as she pedals up the hill at constant speed.

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[3]

(b) Explain how the law of conservation of energy applies to the complete journey from A to B.

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[1]

(c) At one point in the journey, the gravitational potential energy of the cyclist has increased by 5400 J. The mass of the cyclist is 60 kg. The gravitational field strength is 10 N / kg.

Calculate the height above A of the cyclist at this point.

height above A = ................................................[2]

3

2

1

4

Dedicated to My Son Mohammad Irtaza Zain. Code 5054 [Turn over

6 MCQ SECTION: [Total Marks] Two farmers use an electrically powered elevator to lift bales of hay. All the bales of hay have the

same mass.

bale of hay

As sunset approaches, they increase the speed of the motor so that more bales are lifted up in a given time.

How does this affect the work done in lifting each bale and the useful output power of the motor?

work done in lifting each bale

useful output power of the motor

A increases decreases

B increases increases

C no change decreases

D no change increases

Which row gives an example of the stated form of energy?

form of energy example

A gravitational the energy due to the movement of a train along a level track

B internal the energy due to the flow of cathode rays in a cathode-ray tube

C kinetic the energy due to the position of a swimmer standing on a

high diving board

D strain the energy due to the compression of springs in a car seat

Which energy resource is used to generate electricity by first boiling water?

A hydroelectric

B nuclear fission

C tides

D waves

6

5

44

5

Dedicated to My Son Mohammad Irtaza Zain. Code 5054

6 A B C D

5 A B C D

4 A B C D

3 A B C D

2 A B C D

1 A B C D

MCQ Answer Sheet

A car is driven on a long journey along a flat, horizontal road. The car stops several times on the journey and its engine becomes hot.

Which type of energy does not change during the journey?

A the chemical energy in the fuel tank

B the gravitational energy of the car

C the internal (thermal) energy of the engine

D the kinetic energy of the car

Energy is stored in a battery and in a box of matches.

Which type of energy is stored in each of them?

a battery a box of matches

A chemical chemical

B chemical internal (thermal)

C electrical chemical

D electrical internal (thermal)

A man lifts 20 bricks, each of weight 6N.

What other information is needed to calculate the useful work done in lifting the bricks?

A the distance he lifts the bricks

B the mass of the bricks

C the time taken to lift the bricks

D the volume of the bricks