Trial 1 Term1 Stpm 2015 Lengkap Smk Mantin

960/1

STPM 2013

Name :…………………………………….. Class : 6 SF 1

SMK MANTIN

FIRST TERM TRIAL EXAMINATION

PHYSICS One and a half hours (1 ½ HOURS)

DO NOT OPEN THIS QUESTION PAPER UNTIL YOU ARE TOLD TO DO SO. There are fifteen questions in Section A. For each question, four choices of answers are given. Choose one correct answer and indicate it on the Multiple-choice Answer Sheet provided. Read the instructions on the Multiple choice Answer Sheet very carefully. Answer all questions. Marks will not be deducted for wrong answers.

For examiner’s use marks

objective

Answer all questions in Section B. Write your answers in the spaces provided. Answer any two questions in Section . All essential working should be shown. For numerical answers, unit should be quoted wherever appropriate.

Section A

Begin each answer on a fresh sheet of paper and arrange you r answer in numerical order.

Section B

Answers may be written in either English or Bahasa Malaysia.

15 1 2 1 2 3

Total

A Data Booklet is provided. _______________________________________________________________ This question paper consist of 10 printed pages Prepared by : ………………………......

Verified by : ……………………………

1

Section A [15 marks] Answer all questions in this section 1.

The speed v of waves on a stretched string depends on the tension T and the mass per unit length m of the string. In the equation below, a,b,c and d are dimensionless constants. Which of the following equations are dimensionally consistent? A

2.

B

v  a Tm

T m

C

vc

m T

D

v T m

The drag force acting on a uniform sphere with radius r moving with velocity v in a vicious liquid is given by F  6rv, where η is constant. What is the unit for η? A kgm 1 s 1

3.

vb

B kgm 2 s 1

C

kgm 2 s 2

D

kgm 2 s 1

The graph below represents the motion of a body released from rest, rebounds a few times, and finally stops y

0

time

The quantity on the y-axis represents A 4.

0.18 m

C acceleration

D momentum

B 0.26 m

C 0.33 m

D 0.42 m

A resultant force F acts horizontally on a body of mass m at the surface of the earth produces an acceleration a. If the same force acts horizontally on the same body at the surface of a planet where the force of gravity is 3 times that of earth, the resultant acceleration of the body is A

6.

B velocity

A block of wood with initial speed 0.80 ms-1 slides on a rough horizontal surface. Its speed slows down to0.30 ms-1 after it moves a distance of 2.0 m. How much further will it move before its stop? A

5.

displacement

a 9

B

a 3

C

\a

D

3a

A body of mass 2.0 kg is acted upon by a force which varies with time as shown in the figure below; Force/N 10 0 2 4 6 time/s The momentum gained by the body in time 10 s in kg m s-1 is A 40

7.

B 60

C

80

D

100

The figure below shows a marble placed on a smooth track at A of height 0.50 m from the ground. 2

The radius of the loop is 0.10 m. The speed of the marble at the top of the loop at C is A 2.4 ms-1 8.

3.4 ms-1

C 4.4 m s-1

D 5.4 ms-1

The gravitational potential energy of a body of mass 1.0 kg at the surface of the earth is -6.3 x 107 J. What is the minimum velocity of the body so that it can escape to infinity where the potential energy is zero? A 2.8 x10 3 ms 1

9.

B

B

6.3 x10 3 ms 1

C 1.1x10 4 ms 1

D 3.7 x10 4 ms 1

The figure shows a flywheel fixed to a horizontal axle. The diameter of the flywheel is 40.0 cm and the diameter of the axle is 10.0 cm. Tangential forces of 20N and 30 N are applied to the flywheel and axle respectively.

What is the net torque acting on the system? A 2.5 N 10.

B

2.8 N

C

3.1 N

D

3.4 N

A uniform rod of length 1.0 m is supported by two cords at points 0.20 m and 0.40 m from its ends as shown in the diagram. The tensions in the cords are T1 and T2 respectively.

What is the ratio of T1 to T2 ? A 1 : 2

B

1 : 3

C

2 : 1

D

3 : 1

3

11.

The figure below shows a uniform rod AB of weight W hinged at A and the end B supported by a horizontal wire BC.

Which of the following diagram correctly shows the force acting at end A of the rod?

12.

The figure below shows two metal rod X and Y of the same cross-ssectional areas joined at one end . The length of X is twice that of Y, and the Young’s modulus of X is also twice that of Y.

A tensile force is applied to the free ends of the wires. Which of the following statements is not true? A The tension in both the rods are the same B The stress in both the rods are the same 13.

C The strain of both the rods are the same D The extension of both the rods are the same

The r.m.s speed of the gas molecules is v. The pressure of the gas is kept constant. If the volume of the gas is doubled, the root mean square speed of the molecules is A

1 v 2

B

1 2

v

C

2v

D 2v

4

14.

The molar heat capacity of a gas at constant volume is smaller than that at constant pressure because at constant volume A no work done against external pressure B less heat energy is required because the decrease in internal energy of the gas is less C the frequency of collision of the molecules with the wall of the containing vessel has to be kept constant D less heat is required as the average kinetic energy of the molecules decreases

15.

One side of a room consists of a brick wall and a glass window. Both the brick wall and the glass window have the same surface area. The thickness of the brick wall is 30 times that of the glass window, and thermal conductivity of the brick is

1 that of the glass. The ratio of rate of heat flow 6

through the brick wall to that of the glass window is A

1 180

B

1 5

C 5

D 180

SECTION B [15 marks] 5

(Structured Questions) Answer all questions 16.(a)

State the principle of conservation of linear momentum

[2]

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

(b) A boy with mass 60 kg jumped with velocity 3.3 ms-1 to a platform from a boat of 200 kg mass (i) Find the total momentum of the system

[1]

............................................................................................................................................................. ............................................................................................................................................................. (ii) Find the initial and final momentum of the boy

[2]

............................................................................................................................................................. ............................................................................................................................................................. ............................................................................................................................................................. (iii)

Calculate the velocity of the boat when the boy jumped out from the boat to the platform. [2] ........................................................................................................................................................... ............................................................................................................................................................ ............................................................................................................................................................ .............................................................................................................................................................

6

17.

The mass of the planet Neptune is 1.02 x 1026 kg, it has a radius of 24746 km and the planet is spherical. Neptune rotates on its axis with a period of 16.11 hours. (a) What is the gravitational field on the Neptune surface?

[1]

............................................................................................................................................................. ............................................................................................................................................................. ............................................................................................................................................................. (b) Find the weight of a 100 kg space orbiter that has landed on its surface.

[2]

............................................................................................................................................................. ............................................................................................................................................................. ............................................................................................................................................................. (c) What is the centripetal acceleration of an object at the equator of the planet?

[3]

............................................................................................................................................................. ............................................................................................................................................................. ............................................................................................................................................................. ............................................................................................................................................................. (d) What force is necessary to cause this acceleration for a 1500 kg space orbiter?

[2]

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

Section C [30 marks] 7

Answer any two questions in this section. 18.

(a)

Define the work done on an object and state the work-energy theorem.

[2]

(b)

Describe the process in which mechanical energy is converted to thermal energy.

[2]

(c)

The diagram below shows a block of 30 kg slides down a rough plane with an acceleration of 1.5 ms-2. The plane makes an angle of 28o with the horizontal and is 8.0 m long. Find

(i) the kinetic energy of the block when it reaches the bottom of the incline (ii) the work done to overcome friction (iii) the frictional force that acts on the block [3] (iv)the coefficient of kinetic friction between the block and the plane

[3] [3]

[2]

8

19. (a)

A wire of unextended length l and cross sectional area A extends elastically by an amount ∆l when the tension in the wire is increased by an amount F. Write down an expression in term of l, ∆l, A and F for (i) the spring constant k of the wire. [1] (ii)

(b)

the Young modulus E of the material of the wire.

[1]

In order to determine the Young Modulus of the metal of a wire, a student set up the apparatus illustrated in figure below scale 1.4m

Fixed point

8.50 pulley

mass

The length of wire between the fixed end and the pulley is 1.4 m and the area of cross section of the wire is 6.2  10 7 m 2 . The wire passes over the pulley and is held taut by a mass attached its free end. When the mass attached to the end of the wire is increased by 7.0kg, a pointer attached to the pulley rotates trough an angle of 8.5 0 .

to

(i) The pulley has diameter 1.6cm. The wire does not slip over the pulley as the pulley turns. Show that the extension of the wire resulting from the increased mass on its end is 1.2mm. [2] (c)Calculate (i)

the increase in the stress in the wire

[2]

(ii) the increase in the strain of the wire

[2]

(iii) the Young modulus of the material of the wire

[2]

(d)(i) (ii)

Sketch a graph to show the variation with load F on the wire of its extension ∆l . Assume that the elastic limit is not exceeded. [1] Use your graph to show that the strain energy E s stored in the wire given by the expression Es 

1 k () 2 2

Where k is the spring constant of the wire.

[2]

(iii) For a total mass of 8.0kg attached to the wire, the wire extends by 1.37 mm. Calculate the strain energy stored in the wire for this extension. [2]

9

20.

(a)

(b)

The equation

p

1   c 2  may be derived using kinetic theory. 3

 c2  .

(i)

Explain what is meant by the symbol

(ii)

Show that this equation is homogeneous.

[1] [2]

The variation of density  of a gas with pressure p was determined at 290 K and at another temperature T. The results are shown in figure below.

(i)

Comment whether the gas above behaves as an ideal gas.

[3]

(ii)

Determine the root-mean-square speed of the molecules of the gas at 290 K.

[3]

(iii)

Deduce whether the temperature T is greater or less than 290 K.

[3]

(iv)

Calculate the temperature T.

[3]

10