Transcript
Page 1: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

Section A[60 marks]

Answer all questions.

1 Diagram 1.1 shows a vernier calipers.

(a) Name the part labeled Z.

[1 mark]

(b) State the function of Z.

[1 mark]

(c) Diagram 1.2 shows the reading of the vernier calipers when the jaws is closed.

Based on Diagram 1.2: (i) Name the type of error occurred.

[1 mark]

(ii) State the value of the error.

[1 mark]

1/17

Main Scale

Vernier Scale

Page 2: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

2

Diagram 2 shows a circular track with diameter, PQ, 20 m. A runner runs from P to Q through R in 18 s.(a) What is the difference between velocity and speed?

[1 mark](b) What is the average speed of the runner from P to Q?

[2marks](c) What is the velocity of the runner from P to Q?

[2marks]

2/17

Diagram 2

Page 3: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

3 Diagram 3 shows the pistol and bullet of mass 0.05 kg after the pistol has been fired. The momentum of recoils pistol backwards is 10 kg m s-1.

(a) What is the meaning of momentum?

[1 mark]

(b) In terms of momentum, explain why the bullet moves forward with high velocity.

[2marks]

(c) By using the principle of conservation of momentum,

(i) what is the momentum of the bullet.

[1 mark]

(ii) calculate the velocity of the bullet.

[2marks]

3/17

Diagram 3

Page 4: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

4 Diagram 4 shows a worker lifting a load of mass 20 kg using a pulley system. The worker applies a force of 220 N to pull the rope down a distance of 0.5 m. The load is raised to a height of 0.5 m.

(a) What is meant by work?

[1 mark]

(b) Calculate the work done(i) by the worker to pull the rope down a distance of 0.5 m.

[2marks]

(ii) on the load to raise it to a height of 0.5 m.

[2marks]

(c) (i) Compare the work done in 4(b)(i) and 4(b)(ii).

[1 mark]

(ii) State why there is a difference between the work done in 4(b)(i) and 4(b)(ii).

[1 mark]

4/17

Page 5: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

5 A trolley of mass 5 kg is pulled along a horizontal table by a 3 kg weight as shown in Diagram 5. The friction between the trolley and the table is 5 N and the acceleration due to gravity is 10 m s-2.

Diagram 5.1

(a) Find the resultant force that acts on the system.

[1mark]

(b) What is the acceleration of both the trolley and the 3 kg weight?

[2marks]

(c) Label the direction of the force of friction, and the tensions in the string that acts on the trolley as well as the 3 kg weight in Diagram 5.

[3marks]

(d) Calculate the tension in the string that connects the trolley to the 3 kg weight.

[2marks]

5/17

Diagram 5

Page 6: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

6 A student studies the effect of the movement of a lift on the readings of a weighing scale. The mass of the student is 50 kg.In this study, the student stands on a weighing scale in a lift as shown in Diagram 6.

He records the reading of the weighing scale when the lift is at rest, moving up with acceleration,moving up with uniform velocity, moving down with uniform velocity and moving down withdeceleration.The readings of the weighing scale in the study are shown in Table 6.

Movement of the lift Readings of the weighing scale / kgAt rest 50Moving up with acceleration 60Moving up with uniform velocity 50Moving down with uniform velocity 50Moving down with deceleration 60

Table 6

(a) The mass of the student is 50 kg.What is the weight of the student in newtons?

[1 mark]

(b) State two types of movement of the lift when the reading on the weighing scale is equal to the mass of the student.

1.

2.

[2marks]

(c) F is a resultant force that acts on the student.R is the normal reaction of the weighing scale on the student.m is the mass of the student.g is the gravitational acceleration.Write a general equation to show the relationship between F, R, m and g.

[1 mark]

6/17

Diagram 6.1Diagram 6

Page 7: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

(d) When the lift moves up with acceleration, the normal reaction is greater than his weight.Explain why.

[2marks]

(e) (i) What is observed on the reading of the weighing scale when the lift moves down with acceleration?

[1 mark]

(ii) Give a reason for your answer in (e)(i).

[1 mark]

7 Diagram 7.1 shows a toy car released from point P and moved down an inclined track towards point Q with acceleration, a m s-2. The toy car stopped at point R.Diagram 7.2 shows a velocity-time graph that represents the movement of the toy car.

7/17

Page 8: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

(a) Which section the toy car accelerate?

[1 mark]

(b) Which section the toy car decelerate?

[1 mark]

(c) Calculate(i) acceleration of the toy car.

[2marks]

(ii) displacement of section QR.

[2marks]

(d) The toy car cannot move further than point R. Some modifications need to be done to the shape of the toy car and the surface of the track to increase the displacement further than point R.

State the suitable modification and give one reason for the modification.

(i) Shape of the toy car:

Reason:

[2marks]

(ii) Surface of the track:

Reason:

[2marks]

8/17

Page 9: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

8 Diagram 8.1 and Diagram 8.2 shows two identical mirrors which are hung on the wall using strings, of the same length.

The two mirrors are in equilibrium state. Each mirror has a mass of 2 kg. Each string can withstand a maximum force of 15 N.

(a) What is meant by equilibrium state?

[1 mark]

(b) What is the weight of any one of the mirror?

[1 mark]

(c) In the space below, draw a diagram of a triangle of forces that acts on the mirror in Diagram 8.1 and Diagram 8.2.

Diagram of a triangle of forces for Diagram 8.1

Diagram of a triangle of forces for Diagram 8.2

[2marks]

9/17

Page 10: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

(d) T1 and T2 are the tensions of the strings that act on the mirrors in Diagram 8.1 and Diagram 8.2 respectively.(i) In the space below, draw the scale drawings of the triangles of forces to determine

the values of T1 and T2.[Use the scale 1 cm : 2 N]

T1 = cm= N

T2 = cm= N

[4marks]

(ii) Based on your answer in 8(d)(i), which is the most suitable method to hang the mirror? Give one reason for your answer.

[2marks]

(e) If the string in Diagram 8.1 is cut, the mirror will fall down in 0.6 s.Calculate the final velocity of the mirror before it touches the surface of the floor.

[2 marks]10/17

Page 11: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

Section B[20 marks]

Answer any one question from this section.

9 (a) Diagram 9.1 shows two identical steel balls placed onto spring M and spring N. Both springs are elastic and fixed to a horizontal surface. The springs are pushed down until the lengths of spring M and spring N are the same.Diagram 9.2 shows the maximum heights reached by the balls when the hands are released.[Assume spring M and spring N are of the same material, same coil diameter and same original length]

(i) What is the meaning of elasticity?[1mark]

(ii) Using Diagram 9.1 and Diagram 9.2, compare the thickness of the spring wire and the maximum height reached by the balls.Relate the thickness of the spring wire with the maximum height of the ball to make a deduction regarding the relationship between the thickness of the spring wire and the elastic potential energy of the spring.

[5 marks]

(b) The forces use to compress the springs in Diagram 9.1(a)and Diagram 9.1(b) are F1 and F2 respectively.(i) Compare F1 and F2.

Give one reason for this answer.[2marks]

(ii) Using Diagram 9.1 and Diagram 9.2, state the energy changes that take place from the moment the spring is compressed until the ball reaches its maximum height.

[2 marks]

11/17

Page 12: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

(c) Diagram 9.3 shows a pole vaulter performing a jump.

Using appropriate physics concepts, explain the use of suitable equipment and techniques to improve his performance.Your answer should include the following aspects:(i) Vaulter’s attire(ii) Vaulter’s movement(iii) Pole used(iv) Safety

[10marks]

10 Diagram 10.1 shows two similar lorries, P which has no load and Q which has load in front of a traffic light. When green light comes on, both lorries move simultaneously using the same force. Diagram 10.2 shows the position of lorry P and Q after 5 s.

(a) What is meant by acceleration?[1mark]

(b) (i) Using Diagram 10.1 and Diagram 10.2, compare the mass of lorry P and lorry Q, the distance travel and velocity by lorry P and lorry Q after the green light comes on.

(ii) State the relationship between (a) the mass and the distance travelled by the lorries,(b) the mass and the acceleration of the lorries.

[5marks]

12/17

Diagram 10.1 Diagram 10.2

Page 13: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

(c) Diagram 10.3 shows a car is moving with constant velocity on a road.

(i) Draw the free body diagram to mark and label the forces exerted on the car.(ii) Explain why the car moves with constant velocity.

[4marks]

(d) Diagram 10.4 shows a cyclist riding on his bicycle at top speed.

You are required to give some suggestions to design a bicycle which can travel faster. Using the knowledge on motion, forces and the properties of materials, explain the suggestions based on the following aspects:(i) the position of the seat and the handle,(ii) the attire of the cyclist,(iii) the material used for the bicycle,(iv) the size of the tyre,(v) other component for its motion.

[10 marks]

13/17

Diagram 10.3

Diagram 10.4

Page 14: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

Section C[20 marks]

Answer any one question from this section.

11 Diagram 11.1 shows Newton’s cradle which consists of five identical balls suspended in a row from a wooden frame by wires.

When the ball on left end is pulled aside (Diagram 11.2) and allowed to fall, the ball on the far end isknocked away from the others with the same speed as the first ball (Diagram 11.3).

(a) Name the Physics principle involved which makes the ball on the other far end is knocked away from the others.

[1mark]

(b) Explain in term of momentum and energy transfer, why the ball on the opposite end is knocked away from the others.

[4marks]

14/17

Page 15: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

(c) Diagram 11.4 shows five designs of Newton’s Cradle, P, Q, R, S and T, with different specifications. You are required to determine the most suitable design to make the ball at the end swings up to higher level and at bigger speed. Study all the five designs from the following aspects:- The arrangement of the balls- The type of material used to make the balls- The number of string used to hang the balls- The position of the ball to start the oscillation

Newton’s Cradle PMaterial used to make the balls:

Rubber

Newton’s Cradle QMaterial used to make the balls:

Steel

Newton’s Cradle RMaterial used to make the balls:

Steel

Newton’s Cradle SMaterial used to make the balls:

Steel

Newton’s Cradle TMaterial used to make the balls:

Rubber

Explain the suitability of the aspects. Justify your choice.[10marks]

15/17

Diagram 11.4

Page 16: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

(d) In a game, a 50 g white ball of speed 0.8 m s-1 hits a 30 g red ball at rest. If the white ball stops after the collision, calculate:(i) the velocity of the red ball after the elastic collision.(ii) the change of momentum of the white ball.(iii) the impulsive force acting on the white ball during the collision if it is stopped in

0.05 s.[5marks]

12 Diagram 12.1 shows a boy of mass 40 kg sliding in two identical flumes, one after another.

WC= Component of weight parallel to slope

Diagram 12.1 (a) shows the boy sliding down the flume, which is inclined at 30.0O to the horizontal.Diagram 12.1 (b) shows the boy stationary in the flume when the flume is inclined 17.5O to the horizontal.The frictional force acting on the boy in both flumes is 120 N.

(a) What is the meaning of frictional force?[1 mark]

(b) Based on Diagram 12.1 (a), calculate:(i) the component of the weight parallel to the slope of the flume, WC.

[2marks]

(ii) the resultant force acting on the boy.[1 mark]

(iii) the acceleration of the boy.[2 marks]

(c) Using the concept of force, explain why the boy slides down the flume when the angle of inclination is 30.0O and remains stationary when the angle of inclination is 17.5O.

[4marks]

16/17

Diagram 12.1 (a) Diagram 12.1 (b)

Page 17: Peperiksaan Pertengahan Tahun 2014 Fizik Kertas 2

(d) Diagram 12.2 shows four lawnmovers, J, K, L and M with different specifications.You are required to determine the most suitable lawnmover to cut grass effectively.

Lawnmover, J

Lawnmover, K

Lawnmover, L

Lawnmover, M

Diagram 12.2

Study the specifications of the four lawnmovers based on following aspects:- Method of moving the lawnmover.- Mass of the lawnmover.- Size of the cutter.- The angle between the handle and the horizontal line.

Explain the suitability of each aspect and then determine the most suitable lawnmover.Give a reason for your choice.

[10 marks]

END OF QUESTION PAPER

17/17