phy094 past years question

8/11/2019 PHY094 Past Years Question

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CONFIDENTIAL

AS/SEP 2011/PHY094/093

UNIVERSITI TEKNOLOGI MARA

FINAL EXAMINATION

COURSE

COURSE CODE

EXAMINATION

TIME

FOUNDATION PHYSICSl PHYSICSI

PHY094/093

SEPTEMBER 2011

3 HOURS

INSTRUCTIONS TO CANDIDATES

1 .

This question paper consists of ten (10) Questions ONLY.

2. Answer ALL questions in the Answer Booklet. Start each answer on a new page.

3. Do not bring any material into the exam ination room unless permission is given by the

invigilator.

4. Please chec k to make sure that this exam ination pack consists o f:

i) the Qu estion Paper

ii) a one - page Append ix

iii) an Ans wer Booklet - p rovided by the Faculty

DO NOT TURNT ISP GEUNTILYOU RE TOLD TO DO SO

This examination paper consists of 6 printed pages

Hak Cipta Universiti Teknologi MARA C O N F ID E N T IA L


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AS/SEP 2011/PHY094/093

QUESTION 3

Figure 1shows a block (mass m

A

) on a sm ooth horizontal surface, connected by a thin cord

that passes over a pulley to a second block (m

B

) which h angs vertically.

/7 7

A

^

/7 7

B

Figure 1

a) Draw a free-body diagram for each block, showing the force of gravity on each, the force

(tension) exerted by the cord,and any normal force.

(2 marks)

b) W ith the help of New ton's second law, find the expression for the acceleration of the

system and the tension in terms ofm

A

m

B

and g. Ignore friction and the masses of the

pulley andcord.

3 marks)

c) If/77

A

= 13.0 kg andm

B

= 5.0 kg, determine the acceleration of each block.

(2 marks)

d) If initially m

A

is at rest 1.250 m from the edge of the table, how long does it take to reach

the edge of the table if the system is allowed to move freely?

(3 marks)

QUESTION 4

A cooling fan is turned off when it is running at 850 rev/min. It turns 1350 revolutions before it

comes to a stop.

a) Wh at was the fan's angular acceleration, assumed constant?

b) How long did it take for the fan to come to a complete stop?

c) How many revolutions would it take in 50 s?

(5 marks)

(3 marks)

(2 marks)

Hak Cipta Universiti Teknologi MARA

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AS/SEP 2011/PHY094/093

QUESTION 5

A 1.50 x 10

3

kg car accelerates uniformly from rest to 1 0.0 m/s in 3.0 s. Find

a) the work done on the car in this time interval

(3 marks)

b) the instantaneous po wer delivered by the engine at r = 2.0 s

(7 m arks)

QUESTION 6

a) A 60.0 g object is attached to a horizontal spring with a force constant of 12.0 N/m a nd

released from rest with amplitude of 25.0 cm. If the surface is frictionless, what is the

velocity of the object when it is halfway to the equilibrium position?

(5 marks)

b) An announceme nt in a school is made through a speaker on awall. The first student

listens to it 2.00 m from the s peaker with the intensity of 4. 60 * 10

6

W /m

2

.

i) Find the intensity heard by the second student who is 6.20 m from the speaker.

(3 marks)

ii) Find the power output of the speak er's soun d.

(2 m arks)

QUESTION 7

a) State Archim edes' Principle.

(2 marks)

b) An air ma ttress wh ich is 6.5 m long, 3.75 m wide, and 0.20 m thick, has a mass of

0.22 kg. The m attress floats in fresh wa ter.

i) Calculate the buoyan t force of the air ma ttress.

(3 marks)

ii) W hat is the ma ximum mass it can support in fresh wate r?

(5 marks)


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AS/SEP 2011/PHY094/093

QUESTION 8

A pendulum consists of a large weight suspended by a steel wire that is 0.9500 m

long.

[Coefficient of linear expansion for the wire is 12.00 x 10

6

K

1

]

a) If the temp erature increases , does the period of the pendulum increase s, decreases or

stay the sam e? E xplain.

(2 m arks)

b) Calculate the chang e in length of the pendulum if the temp erature increase is 1 50.0 C .

(3marks)

c) Calculate the period of the pendulum before and after the tempe rature increase.

[Taking

g

= 9.81 m/s

2

at the location of the pendulum.]

(5 marks)

QUESTION 9

a) A 1 35 g lead ball at a temp erature of 64.2 C is placed in a light calorimeter con taining

122 g of water at 20.5 C . Find the equilibrium tempe rature of the system.

[c

Pb

= 128 J/kg K, c^er = 4186 J/kg K]

(5 marks)

b) How much heat is needed to melt 37.40 kg of silver that is initially at 23. 0 C?

[c

S

ii

V

er = 230 J/kg K,

U

guv*: = 0.88 J/kg]

(2 marks)

c) How much heat must be absorbed by ice of mass m =850 g at -1 5 C to chan ge it to

liquid at 16 C ?

[c

ice

= 2220 J/kg K,

c

water

= 41 86 J/kg K,L

r

wa

e

r=41 86 J/kg K]

(3 marks)


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AS/SEP 2011/PHY094/093

QUESTION 10

a)

b)

A basketball player does 2.43 x 10

5

J of work during her time in the game, and

evaporates 0.110 kg of water. Assuming the latent heat of water is 2.26 x 10

6

J/kg for

the perspiration, determine the change in the player's internal energy.

(4 marks)

An ideal gas is slowly compressed at a constant pressure of 2.0 atm from 10.0 L to

2.0 L as shown in Figure 2.Heat is then added to the gas, holding the volume con stant,

and the pressure and temperature are allowed to rise (line DA until the temperature

reaches its original value (7

A

= f

B

) .

Isothermal

0 4

6 8 1 0 V L )

Figure 2

i) Convert 2.0 L and 1 0.0L to cubic meters.

ii) Convert 2.0 atm to N/m

2

.

iii) Calculate the total work done by the gas in the process BDA.

(2 marks)

(1 mark)

(3 marks)

END OF QUESTION PAPER


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CONFIDENTIAL APPENDIX AS/SEP 2011 /PHY094/093

F O R M U L A S

v

=

v

0

+at P

=

x - x

0

=

vj

at

2

v =Acos{cot q

v

2

=v]+2a{x-x

0

) v=

a4 A

2

-x

2

-

V V

o T

P

V

I =

2 A

F

=

ma F

B

=

pVg

co =

co

0

+at AL

=

aL

0

AT

0-0=cot

-a t

2

T

=

2n\-

2 \g

ca

2

=

phy094 past years question

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