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FIFHTHBIFI UI'HVERSITY

OF SCIENCE nnD TECHNOLOGY

FACULTY OF HEALTH AND APPLIED SCIENCES

DEPARTMENT OF NATURAL AND APPLIED SCIENCES

QUALIFICATION: BACHELOR OF SCIENCE (MAJOR AND MINOR)

QUALIFICATION CODE: 07BOSC LEVEL: 5

COURSE CODE: GNP501S COURSE NAME: GENERAL PHYSICS 1A

SESSION: JUNE 2017 PAPER: THEORY

DURATION: 3 HOURS MARKS: 100

FIRST OPPORTUNITY EXAMINATION PAPER

EXAMINER(S) DR. SYLVANUS ONJEFU

MODERATOR: DR. DIPTI SAHU

INSTRUCTIONS

1. Write all your answers in the answer booklet provided.

2. Read the whole question before answering.

3. Begin each question on a new page.

PERMISSIBLE MATERIALS

1. Scientific Calculator

THIS QUESTION PAPER CONSISTS OF 7 PAGES

(INCLUDING THIS FRONT PAGE)

SECTION A

QUESTION 1

Multiple choice questions types: Each question carries two marks

pow

B.

c.

D. M'lLT'l

B.

C.

D. MLZT1

.0090?

Dimensional analysis is a method used to ...................

A. torture mankind.

convert from one unit into another unit.

cure mental illness.

make kids really mad.

......... is a unit of force.

kg.m/s2

kg

m/s

cm3

Which of the following physical quantity is dimensionless?

A. Angle

B. Strain

C.

D. Allofthe above

Specific gravity

The dimensional formula of angular velocity is ............

A. MLT

MLT2

MoLOT-l

The dimensions of WORK are;

A. MLT

MLZTZ

MLT‘1

The rate of change of displacement of a particle is referred to as .....................

A. speed

B. velocity

C.

D. power

acceleration

[40]

(2)

(2)

(2)

(2)

(2)

(2)

7.

10.

11.

12.

Which of the following is a physical quantity that has a magnitude but no

direction?

A. Vector

B. Frame of reference

C. Resultant

D. Scalar

The difference between speed and velocity is:

A. speed has no units

B. they use different units to represent their magnitude

C. speed shows only magnitude, while velocity represents both magnitude

(strength) and direction

D. velocity has a higher magnitude

A dot product of any two vectors gives a ..................

A. vector

B. vector and scalar

C. scalar

D. unit vector

Which of the following is not true?

A. velocity can be negative

B. velocity is a vector

C. speed is a scalar

D. speed can be negative

The resultant magnitude of two vectors:

A. Is always positive

Can never be negative

Can never be zero.0090 Is usually zero

is the rate of change of energy?

Work

Power

Frequency.00??? Viscosity

(2)

(2)

(2)

(2)

(2)

(2)

13. The forces of 20 N towards north and 12 N towards south are acting on

an object. What will be resultant force?

A. 32 N toward north

B. 20 N towards north

C. 32 N towards south

D. 8 N towards north

14. A toy car moves 8 m in 4 s at the constant velocity. What is the car’s velocity?

A. 1 m/s B. 2 m/s C. 3 m/s D. 4 m/s

15. A train moves at a constant velocity of 50 km/h. How far will it move in 0.5 h?

A. 10 km B. 20 km C. 25 km D. 50 km

16. A boat can move at a constant velocity of 8 km/h in still water. How long will it

take for the boat to move 24 km?

A.2h B.3h C.4h D.6h

The graph represents the relationship between velocity and time for an object

moving in a straight line. Use this graph to answer questions 17 and 18.

13.»: (nuts)

9

17. Which of the following statements is true?

A. The object speeds up

B. The object moves with a constant velocity

C. The object stays at rest

D. The object is in free fall

(2)

(2)

(2)

(2)

(7—)

18. What is the acceleration of the object after 5 s? (2)

A. 0 m/s2 B. 3 m/s C. 4 m/s2 D. 5 m/s2

19. A projectile is fired at an angle of 60.0° above the horizontal with an initial

speed of 30.0 m/s. How long does it take the projectile to reach the highest

point in its trajectory? (2)

A. 1.5 s B. 2.7 s C. 6.2 s D. 9.8 s

20. The property of water whereby molecules tend to stick to one another is called: (2)

A. Cohesion B. Polarity C. Adhesion D. Viscosity

SECTION B

QUESTION 2 [22]

2.1 Derive the dimensions of:

(i) pressure (3)

(ii) surface tension (3)

(iii) Young’s Modulus. (3)

(iv) The coefficient of viscosity of a liquid is defined as:

_

force

Area.x.velocity.gradient

Derive the dimensional unit of 77. (3)

2.2 The velocity V0 for the stream-line flow of a liquid in a small uniform tube depends

on the radius r of the tube, the density p and the coefficient of viscosity nof the

liquid. Use the method of dimensional analysis to obtain an expression for the

velocity V0 and use your result to obtain the value of the constant K if

2

Vfifl’ where Z is the length of liquid (10)4771

QUESTION 3

3.1 Given the three vectors

B=2i—3}+4E

Z=E+2}—3E

_=—3i+6}—4;

Calculate (5 + 5).;

3.2 The position of an object is given by 4.022; — 5t2}+ 3.0; m (with t in seconds).

Determine;

(i) an expression for the rate of change of displacement of the particle

(ii) the magnitude of the velocity when the time is 3.0 seconds

(iii) the angle of the velocity relative to the positive direction of the x-axis at

t = 3.0 seconds.

3.3 A ball is hit with a velocity of 3 m/s at an angle of 60°to the horizontal. Derive;

(i) the time of flight

and calculate

(ii) the time of fight

(iii) the maximum height

(iv) the range.

QUESTION 4

4.1 State the law of conservation of momentum.

4.2 Show that the rate of energy transfer of a particle is given by;

fxv

[19]

(3)

(2)

(2)

(2)

(4)

(2)

(2)

(2)

[7]

(2)

(3)

4.3 Object A of mass 20 kg moving with a velocity of 2 m/s makes a head-on collision

with object B of mass 10 kg moving with a velocity of 2 m/s in the opposite direction.

lfA and B stick together after collision, calculate their common velocity v in the

direction of A. (2)

QUESTION 5 [12]

5.1 A satellite of mass 1000 kg orbits the earth in a circular (orbit) form close to its

surface. If the radius of the earth is 6.4 x 106

m (g = 10 m/sz). Determine;

(i) the velocity ofthe satellite (2)

(ii) the centripetal force of the satellite. (2)

5.2 An object of mass m is attached to a spring of length L. If the spring is extended by

a distance e and released, show that the period of oscillation is given by;

T = 271‘ E,where g is the acceleration due to gravity. (4)

g

QUESTION 6 [6]

6.1 Define the term adhesion. (2)

6.2 Explain surface tension. (2)

6.3 A man visiting the coast was informed of the maximum temperature for that

week. He was told that the maximum temperature will be 34°C. The main challenge

is that this man can only interpret temperature in degree Fahrenheit scale and so if

you are charged with the responsibility to help what will be you answer in degree

Fahrenheit? (2)

END