POLYTECHNIC OF NAMIBIA
http://www.polytechnic.edu.na
School of Engineering
InSTEM
Private bag 13388, Windhoek, Namibia.
Tel: + 264 (61) 2072552 Fax : + 264 (61) 2072142
Introduction to Physics B (IPH402S)
Test 1
31 August 2015
Mark
Percentage
Moderated Mark
Moderated Percentage
Student signature (when moderated)________________________
Student Surname:_____________________
Student nr: ______________ Group nr: ______
Instructions to candidates:
1. Answer all the questions on this question paper.
2. Write all the answers in ink.
3. Examination conditions apply at all times.
4. NO books, notes or correction fluid (Tippex) allowed.
5. Pocket calculators are allowed.
6. You are NOT allowed to borrow or lend any equipment or stationary.
7. No cell phones allowed.
8. This memo consists of four pages including this cover page.
9. All final answers must be rounded off to three decimal places.
10. Use the constant values on the last page in your calculations.
Total Marks:
Duration:
Examiner:
Test 1
50
90 Minutes (1 hour 30 minutes)
I Malan, O Kachepa
Page 1 of 4
2015 IPH402S
POLYTECHNIC OF NAMIBIA
http://www.polytechnic.edu.na
School of Engineering
InSTEM
Private bag 13388, Windhoek, Namibia.
Tel: + 264 (61) 2072552 Fax : + 264 (61) 2072142
Question 1
1.1
1.2
1.3
[7]
Light is referred to as a type of electromagnetic wave. Explain what is meant by the term
electromagnetic wave.
Which type of wave that cannot be polarised? Give a reason for your answer.
A sound wave with a frequency 660 Hz passes through air. The variation of particle
displacement with distance along the wave at one instant of time is shown below.
(2)
(2)
0.5
displacement / mm
00
1.0
2.0
distance / m
–0.5
Use the graph above to determine the following:
1.3.1 the wavelength of the wave
1.3.2 the amplitude of the wave
1.3.3 the speed of the wave
(1)
(1)
(1)
Question 2
[9]
2.1
2.2
(2)
2.3
Test 1
What is the Doppler effect?
Write a formula you would use to calculate the frequency in the Redshift and name the
symbols in the equation.
An alert physics student stands beside the tracks a s train passes by. He notes that the
frequency of the train whistle is 442 Hz when the train is approaching and 441 Hz when the
train is receding. How fast is the train moving?
Page 2 of 4
2015 IPH402S
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(4)
POLYTECHNIC OF NAMIBIA
School of Engineering
http://www.polytechnic.edu.na
InSTEM
Private bag 13388, Windhoek, Namibia.
Tel: + 264 (61) 2072552 Fax : + 264 (61) 2072142
Question 3
[9]
3.1
3.2
3.3
What is buoancy?
State Archimedes’s Principle.
A solid vertical cylinder has a cross-sectional area of 0,45 m2 and is submerged in water.
The top of the cylinder is 1,4 m below the surface of the water and the bottom of the cylinder
is 3,2 m below the surface of the water, as shown below:
(1)
(2)
3.3.1
Calculate the resultant force of the water on the cylinder due to the pressure difference
in the water.
The material of the cylinder has a density of 2400 kg/m3. It is held in position by a
fixed vertical rod, with the top of the cylinder 1,4 m below the water surface (shown below).
Determine the force exerted by the rod on the cylinder.
3.3.2
Test 1
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2015 IPH402S
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(3)
POLYTECHNIC OF NAMIBIA
School of Engineering
http://www.polytechnic.edu.na
InSTEM
Private bag 13388, Windhoek, Namibia.
Tel: + 264 (61) 2072552 Fax : + 264 (61) 2072142
Question 4
4.1
4.2
4.3
4.4
[13]
Differentiate between streamline flow and eddy currents.
How would you identify an ideal fluid?
A 5/8 inch diameter garden hose is used to fill a round swimming pool that is 7,2 m in diameter.
How long will it take to fill the pool to a depth of 1,5 m if the water leaves the hose at a speed
of 0,28 m/s? (1 inch = 2,54 cm)
During each heartbeat approximately 70 cm3 of blood is pushed from the heart at an average
pressure of 105 mmHg. Determinet the power output of the heart in watts, assuming 70 beats
per minute.
Question 5
5.1
5.2
5.3
5.3.1
5.3.2
5.4
(4)
(4)
[12]
Potential difference and emf is defined as energy transferred per unit charge. How can this be
true if the potential difference and emf is not the same thing?
Derive the fomula for power: power = VI.
A battery is labelled 150 Ah.
Determine the time that the battery is able to provide a continuous current of 500 mA.
Calculate the number of electrons which flows past a point in the circuit in this time.
Write all possible equations using Kirchoff’s First and Second Law that you can apply in the
circuit below.
Use the following values in your calculations:
g = 9,8 m/s2
density of pure water = 1000 kg/m3
density of sea water = 1029 kg/m3
elementary charge = 1,6 x 10-19 C
atmospheric pressure = 101,325 kPa
Test 1
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2015 IPH402S
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