NAMIBIA UNIVERSITY OF SCIENCE AND TECHNOLOGY

FACULTY OF HEALTH AND APPLIED SCIENCES

DEPARTMENT OF HEALTH SCIENCES

QUALIFICATION: BACHELOR OF ENVIRONMENTAL HEALTH SCIENCES

BACHELOR OF HEALTH INFORMATION SYSTEMS MANAGEMENT

BACHELOR OF MEDICAL LABOLATORY SCIENCES

BACHELOR OF HUMAN NUTRITION

QUALIFICATION CODE: O8BEHS

O7BHIS LEVEL: 5

O8BMLS

O8BOHN

COURSE CODE: HSP511S COURSE NAME: HEALTH SCIENCE PHYSICS

SESSION: JULY 2018 PAPER: THEORY

DURATION: 3 HOURS MARKS: 100

SUPPLEMENTARY/SECOND OPPORTUNITY EXAMINATION PAPER

EXAMINER(S) | MR. VAINO INDONGO

MODERATOR: | DR DIPTI SAHU

INSTRUCTIONS

hs Write all your answers in the answer booklet provided.

2, Read the whole question before answering.

Begin each question on a new page.

PERMISSIBLE MATERIALS

1. Scientific Calculator

THIS QUESTION PAPER CONSISTS OF 7 PAGES

(INCLUDING THIS FRONT PAGE)

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QUESTION 1 [40]

Multiple choice questions. Choose only one correct answer. Each question carries 2 marks.

11 is expressed as the rate of change displacement. (2)

A. W B. Hz Cc. LT? D. NS

1.2 What are the dimensions of rate of change of velocity? (2)

A. [LT~2] B. [MLT~*] C.[ML2T~2] D. [ML2T2]

1.3 The dimensional formula for kinetic energy is . (2)

A. M2L2T2 B. ML2T2 C. ML*T D. ML*T

1.4 The unit of physical quantity which does not depend on the unit of any other physical

quantity is called as . (2)

A. independent dimension

B. fundamental dimension

C. core dimension

D. none of the above

1.5 Acar moves around a circular track with a constant speed. Which of

the following statements are true concerning this motion? (2)

|. Centripetal force is towards the centre of the circle.

Il. The average speed is zero.

Ill. The acceleration is zero.

A. only lis true B. only Il is true

C. only Ill is true D. both | and III are true

1.6 How long would it take a car that starts from rest and accelerates uniformly

in a straight line at 5 m/s 2 to cover a distance of 400 m? (2)

A. 15.0s B. 7.55 C.8.9s D.12.6s

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1.7 Asoccer ball, at rest on the ground, is kicked with and initial velocity of 18 m/s at a

launched angle of 35°. Determine the time it takes to reach its maximum height, assuming

that its air resistance is negligible.

A. 0.55 B.1.0s C1.7s D. 2.05

1.8 Power is measured in:

A. Ws B. Js C. m/s D. W2

1.9 Which of the following is not a vector quantity?

A. velocity

B. speed

C. acceleration

D. None are vector quantities.

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

Vector

Frame of reference

Resultant

GOP >

Scalar

1.11 The difference between speed and velocity is:

A. speed has no units

o they use different units to represent their magnitude

(2)

(2)

(2)

(2),

(2)

C. speed shows only magnitude, while velocity represents both magnitude (strength) and

direction

D. velocity has a higher magnitude

1.12 A dot product of any two vectors BiVeS a ........eeeceeeee

A. vector

B. vector and scalar

C. scalar

D. unit vector

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(2)

1.13 Which of the following is not true? (2)

A. velocity can be negative

B. velocity is a vector

C. speed is a scalar

D. speed can be negative

1.14 The resultant magnitude of two vectors: (2)

Is always positive

Can never be negative

Can never be zero

990

7 >

Is usually zero

1.15 An airplane that flies at 100 km/h with a 10 km/h tailwind travels at 110 km/h relative to

the ground. If it instead flies into a 10 km/h headwind, its groundspeed is . (2)

A. 90 km/h. B. 100 km/h. C. 110 km/h. D. 120 km/h.

1.16 At one instant an object in free fall is moving upward at 50 meters per second. One second

later its speed is about . (2)

A. 100 m/s. B. 60 m/s. C.50 m/s. D. 40 m/s.

1.17 Acar accelerates from rest at 2 meters per second per second. What is its speed 3 seconds

after the car starts moving?

(2)

A. 2 m/s B. 3 m/s C.4 m/s D. 6 m/s

1.18 Calculate the volume of an ice block with mass of 24.6 g and density

917 kg/m?. (2)

A. 2.68 x 1075 m3 B. 3.1 x 10% m3

C. 19.3 x 10-3 m3 D. 2.0x 102 cm

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1.19 A streamline flow is also called ............ (2)

A. Laminar flow B. Turbulent flow

C. Volume flow D. Bernoulli’s flow

1.20 Asteel bar is precisely 1.6 m at 25° C. At what temperature will its length

be 1.4 mm longer? (2)

A. 48°C B. 98°K C. 48°K D. 98°C

QUESTION 2 [16]

DIMENSIONS AND DIMENSIONAL ANALYSIS

2.1 Match the following physical quantities in Group 1 with their dimensions in Group 2. Write

only the number in Group 1 corresponding to the correct letter in Group 2. (5)

Group 1 Group 2

1. Work done (Energy) (W) ----------------------------- A. [ML?2T~3]

2. Power (P) B.[ML~?T ~*]

3. Momentum (M) C.[ML2T~2] 4. Modulus of elasticity (E) ----------------------------- D.[MLT~-7]

5. Dynamic viscosity (1) E.[ML-*T~-2]

2.2 What is the dimensional formula/dimension of the Universal gravitational constant G if the

— where F is the force of attraction between the two bodies, m1, m2

are the masses of the two bodies and R is the distance between them. Also find the unit of

this universal gravitational constant. (3)

expression F = G

2.3 The mass ‘m’ of the largest stone that can be moved by a flowing river depends upon the

velocity ‘v’ of water, density ‘d’ of water and acceleration due to gravity ‘g’. Use the method

of dimensional analysis to deduce the expression mass of a stone. (8)

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QUESTION 3

VECTORS AND SCALARS, ONE AND TWO-DIMENSIONAL MOTION

3.1 Consider the following vectors:

A=2i-2j+k and B=-4i+2j-k

(i) Find the vector product the two vectors

(ii) Determine the angle between the two vectors.

3.2 Giventhat: A=-2i+3j—4k, find the magnitude of vector A, and the unit vector

in the direction of A.

3.3 Show the derivation for the expression v 2 = u 2 + 2as:

3.4 Apassenger plane moving at 2 m/s has accelerated up a runway at a constant

acceleration of 3 m.s~.

3.4.1 Determine the position and velocity of the plane 5 seconds after it starts to move.

3.4.2 If the speed of 70 m/s is required for take-off, what is the minimum

length of runway required?

QUESTION 4

WORK, ENERGY, POWER AND TWO DIMENSIONAL MOTION

4.1 Define power?

4.2 Show that power is equal to the product of force and velocity.

[19]

(3)

(3)

(3)

(3)

(4)

(3)

[14]

(2)

(3)

4.3 A boy throws a ball with a speed of 40 ms“ at an angle of 30° to the horizontal. Assuming

the ball is projected from ground level, find

(a) the time taken for the ball to reach its greatest height (3) (b) the maximum height at which the ball reached before returning to the ground level (3)

(c) the horizontal distance travelled by the ball

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(3)

QUESTION 5 [11]

CIRCULAR MOTION, SIMPLE HARMONIC MOTION AND UNIVERSAL GRAVITATIONAL, HEAT AND

TEMPERATURE

5.1 A particle of mass 0.5 g is traveling in a circle of radius R = 1.5 m and with an angular

velocity of 10 rad/s. What is the tangential velocity of the particle? (2)

5.2 If you are experiencing a force of 500 N against your seatbelt as you turn a corner

(radius of the curve is 30 m) in a car, how fast must you be traveling in your car if

the mass of your body is 80 kg? (3)

5.3 Aspacecraft of mass 320 kg land on the moon. Calculate the moon’s gravitational

acceleration, g, on the spacecraft. [Take mass of moon = 7.5 x 10% kg, radius of the moon

= 1.6x 10° m, G =6.67 x 10-4 Nm? kg?]. (3)

5.4 During the time when a man had flu, he ran a fever of 2.0°C above normal.

His body temperature was 39.0°C instead of the normal 37.0°C. Assuming

that the man has a mass of 80 kg and that the human body is mostly water,

how much heat is required to raise his temperature? [Take specific heat

capacity of liquid as, c = 4186 J / kg.°C] (3)

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