INSTRUCTIONS TO STUDENTS
 Attempt ALL questions in sections A and B.
 All your answers must be written in the spaces provided in this question paper.
 All working must be clearly shown
 Non programmable silent electronic calculators and KNEC mathematics table may be used except where stated otherwise
SECTION A (25 MARKS)
Answer all the questions in this section
 Figure 1 below shows a scale of vernier calipers when measuring the width of a meter rule.
What is the actual width of the meter rule if the calipers has a zero error of + 0.6mm.? (2mks)  A clinical thermometer has a constriction in the bore just above the bulb. State the use of the constriction. (1mk)
 Figure 2 below shows air trapped by a column of t6he mercury in a Utube . The atmospheric pressure is 76 cm Hg.
At what pressure in mmHg is the enclosed air? (3mks)  A girl of mass 50 Kg runs up a flight of height 4m in 4 seconds . Calculate the power she developed in this time (2mks)
 Name the transducer in the following energy conversions.
 Kinetic to electrical (1mk)
 Solar to heat (1mk)
 Figure 3 below shows dots produced on a tape pulled through a ticker timer by a moving body.
The frequency of the ticker –timer is 50 Hz. Calculate the acceleration of the body. (3mks)  Figure 4 below shows an ammeter used to measure current through the conductor .The student used the lower scale.
State the reading from the meter (1mk)  Figure 5 below shows a uniform rode AE which is 40 cm long. It has a mass of 2Kg and pivoted at D. If 2N is acting at point E , and 30N force is passed through a frictionless pulley.
Find the force X acting at end A. (3Mks)  Convert 200°C into Kelvins (1mk)
 Figure 6 below shows two identical springs constant 3N/cm supporting a load of 30N.
Determine the extension of each spring (3mks)  Explain why a bus should not carry standing passengers. (1mk)
 State TWO reasons mercury is preferred as a barometric liquid and not water . (2mks)
SECTION B (55MARKS)
Answer all questions in this section

 Define the term efficiency as used in machines . (1mk)
 Figure 7 below shows the cross –section of a wheel and axle of radius 6.5 cm and 1.5 cm respectively used to lift a load. Use it to answer the question that follow.
Determine the Mechanical advantages (M.A) of the system (2mks)
 Velocity ratio (V.R) of the system (2mks)
 Efficiency of the machine (2mks)
 Give one reason why the above machine is not 100% efficient (1mk)
 State the law of conservation of energy (1mk)

 In inelastic collision , kinetic Energy is lost .Explain . (1mk)
 A Trailer of mass 30 tonnes travelling at a velocity of Km/ her rams onto a stationery bus of mass 10 tonnes . The two move together after impact. Determine the common velocity at which they move after impact. (3 Mks)
 A stone is thrown vertically upward with an initial velocity of 30 M/s
 Determine the maximum height reached. (2mks)
 Time taken to come back to the point of projection (2mks)
 The figure 6 below shows a body being pulled by a constant force of 10N for 4m over wooden surface . The co efficient of friction is 0.03.
Find the acceleration of the body (3mks)

 State Hooke’s law (1mk)
 A graph of force (yaxis) against (xaxis) is provided. Use it to answer questions below.
From the graph determine; Work done in stretching the spring by 3cm. (3mks)
 Spring constant .Give your answer in SI Units. (3mks)
 State two factors that affect the spring constant. (2mks)

 Give reason why ink is likely to ooze a pen when one is up in an airplane. (1mk)
 The figure below is a simple hydraulic machine used to raise heavy loads.
Calculate; The pressure exerted on the oil by the force applied at A (2mks)
 The load raised at B (2mks)
 Give two properties which make the oil suitable for use in this machine . (2mks)
 The barometer reading at the base of the mountain is 60cm/ Hg while at the top is 50 cm/Hg. If the densities of air and mercury are 1.25kgm^{3} and 13,600kgm^{3} respectively. Calculate the height of the mountain. (3mks)

 Distinguish between streamline and turbulent flow. (2mks)
 Figure below shows two light sheets of paper arranged as shown
Explain the observation made when air is blown at the same time at point A and B. (2mks)  Figure 12 below shows an incompressible fluid moving through a tube of varied crosssection area. If the area of the small tube is 0.05m^{2}, Calculate the area of large tube in cm^{2}. (3mks)
 State the Bernoulli’s principle (1mks)
 State any TWO assumptions made when deriving the equation of continuity (2mks)

 State the principal of moments (1mk)
 A uniform metal strip is 3.0cm wide, 0.5 cm thick and 100 cm long. The density of the metal is 2.7 g/cm^{3}. Determine
 The weight of the Metal strip. (2mks)
 The strip is placed on a pivot and kept in equilibrium by forces in the figure below.
 Determine the value of F . (3mks)
MARKING SCHEME
SECTION A
 MSR = 6.90cm
VSR = 0.04cm
= (6.90+ 0.04) cm
Actual width = 6.94cm0.06
= 6.58cm 2 marks  It prevents the return of the mercury to the bulb when the thermometer is removed from the body to the surrounding
1mark  Pressure = Press. Due to atm. + press. due to liquid column
= (76+50) cmHg
= 126cmHg OR 1260mmHg 3 marks  Power = work done = mgh
Time Time
Power = 50 x 10 x 4
4
Power = 500W 2 marks 
 Dynamo 1 mark
 Solar panel 1 mark
 V = 5 = 250 cm/s
0.02
U = 2 = 100m/s
0.02
a= v−u
t
a = 250 −100
0.06
a = 2500cm/s² or 25cm/s² 3 marks  Reading =1.35 A 1mark
 30 x 20 + 10 x 2 = 30 x +10W
600 + 20 =30X +200
620 = 30X +200
X = 14N 3MKS  −200 + 273=73K Working must not be shown 1 marks
 e = F
e = 30
2×3
e =5cm 3marks  Standing passengers raise the center of gravity making the bus unstable

 Mercury has a higher density than water
 Mercury does not stick on walls of the glass 2mks
SECTION B

 Efficiency is the ratio of work done on the load(work output) to the work done by the effort(work input) expressed as a percentage 1mk

 MA = L
E
MA= 150
50
= 3 2mks  VR = 2πR
2πr
VR = 2π x 6.5
2 π 1.5
= 4.333 2mks  efficiency = MA X100
VR
efficiency = 3 x 100
4.333
= 69.23% 2mks  the friction between the moving parts 1mk
 MA = L
 The sum of kinetic energy and potential energy of a system is constant
Or
Energy can neither be created nor destroyed but can only be changed from one form to another 1mk
9 marks

 The bodies undergo deformation
OR
Some of the energy is transformed to heat, sound or light 1mk  M_{1}v_{1} + m_{2}v_{2} = v(m_{1} + m_{2})
30000 x 20 + 10000 x 0 = v(30000 + 10000)
600000 = v(40000)
V = 15m/s 3mks 
 ^{h}max = u²
g
^{h}max = 30²
10
= 90m 2mks  T = 2u
g
T = 2 x 30
10
= 6s 2mks
 ^{h}max = u²
 F_{r} = µR
F_{r} = 0.03 x 5x 10
=1.5N
Resultant force = 10 − 1.5
= 8.5N
F = ma
8.5 = 5a
α = 1.7m/s² 3mks
11mks
 The bodies undergo deformation

 For a helical spring or any other elastic material, extension is directly proportional to the stretching force provided the elastic limit is not exceeded 1mk

 work done = area under the graph
Work done = ½ Fe
Work done = ½ x 6 x 0.06
= 0.18j 3mks  spring constant = gradient of the graph
= Δ force
Δ Extension
= 6 − 0
0.06 − 0
= 100N/m 3mks 
 Nature of the material of the spring
 Thickness of the wire of the spring
 The diameter of the spring
 The number of turns per unit length 2mks
 work done = area under the graph

 There is low atmospheric pressure hence the ink pressure in the pen is higher, forcing the ink out 1mk

 p = force
Area
p = 120
0.006
p = 20000 pa 2mks  20000 = F
0.5
Load = 10000N 2mks 
 Oil is incompressible
 The oil does not corrode the parts the machine
 Have a high boiling point and a low freezing point 2mks
 p = force
 Pressure due to air column = Pressure difference
h_{a}ę_{a}g = h_{m}ę_{m}g
h_{a} = hₘęₘ_{} ęa
ha = 0.1x13600
1.25
= 1088m 3mks
10mks

 Streamline flow is a flow in which all particles of the fluid at a point in a tube of flow are travelling at the same velocity and same direction while turbulent flow is a flow in which particles at a point move with different speeds and in different direction. 2 mks
 The papers move away from each other, the fast moving area reduces the pressure; the atmospheric pressure in between the papers pushes them apart 2 mks
 A1v1 = A2 V2
A1 = 0.056 X 2.5
0.6
= 0.233cm² 3mks  Provided the fluid is non  viscous, incompressible and flowing steadily, an increase in speed of the fluid produces a corresponding decrease in pressure. 1 mks

 the fluid in incompressible
 the fluid is non  viscous
 the flow is streamlined Any 2 x 1 = 2mks
10 marks

 For a system in equilibrium, the sum of clockwise moments must be equal to the sum of ant  clockwise moments at a point of support.

 w = 0.03 x 0.005 x 2700 x 10
W = 4.05N 2mk  Sum of clockwise moments  sum of the anticlockwise moments
20 x F = 15 x 4.05
F = 3.0375 N 3mks
06 marks
 w = 0.03 x 0.005 x 2700 x 10
Download Physics Paper 1 Questions and Answers  Bungoma Diocese Mock Exams 2021/2022.
Tap Here to Download for 50/
Get on WhatsApp for 50/
Why download?
 ✔ To read offline at any time.
 ✔ To Print at your convenience
 ✔ Share Easily with Friends / Students
Join our whatsapp group for latest updates