INSTRUCTIONS
ANSWER ALL QUESTIONS IN THE SPACE PROVIDED.
 30cm^{3} of petrol is mixed with 40cm^{3} of kerosene. If the density of petrol is 0.70gcm^{3} and kerosene is 0.80gcm^{3}. Calculate the density of the mixture. (3mks)
 60 drops of water are transferred to a beaker from a burette. The level of water in the burette fall from 17cm^{3} mark to 20cm^{3} mark. Calculate the volume of I drop of water (3mks)
 Name the forces acting on
 A box resting on a bench
 Between the wheels of a moving car and the road
 On an object immersed in water
 Between n pole and spole of a magnet
 Between water poured on glass and the glass surface.

 State two practical applications of friction force in our daily lives. (3mks)
 List three ways in which friction force can be reduced. (3mks)
 The figure below shows a form of a hydraulic lift.
Using Pascal’s principle, determine the forces F2 on the small piston to lift the load. (4mks)  Study the setup below and answer the questions that follows
 What observation would be made in the tube after some time. (1mk).
 Indicate in the diagram the likely position where the observation stated in (a) above would take place. (1mk)

 When taking care of a lead acid accumulator, what must be done if the
 Density of the acid becomes too low. (1mk)
 Level of the acid becomes too low. (1mk)
 An echo sound sends sound signals to the bottom of a lake and receives them back after 0.08s. Find the depth of the lake. (Take the speed of sound in water 1400m/s) (2mks)
 When taking care of a lead acid accumulator, what must be done if the
 The velocity of light in water is 2.2 x 108ms and the velocity of light in a diamond is 1.24 x.108m/s. Calculate
 Retractive index of light passing from water to diamond. (3mks)
 The critical angle for water is 48.6º Calculate the refractive index of water. (2mks)
 State the applications of total internal reflections.
 The figure below shows sound waves emitted by a drum struck.
Explain why the wave fronts are directed to the around (2mks)  A solid weighs 32.5N on the surface of the moon. The force of gravity on the moon is 1.7Nkg^{1}. Determine the mass of the solid. (3marks)
 The figure below shows a Bunsen – burner.
Use the Bernoulli’s principle to explain how air is drawn into the burner when the gas tap is opened. (3mks)  Using a well labeled diagrams, show three states of equilibrium. (3mks)
Define the moment of a force. (2mk) 
 What is a luminar flow? (1mk)
 State two assumptions needed in derivation of equation of continuity. (2mks)
 State two effects of Bernoulli’s principle. (2mks)


 State Newton’s first law of motion. (1mk)
 Give a reason why it is important that passenger’s in moving vehicles put on safety belts. (2mks)

 A boy of mass 60kg stands on a balance in a lift which is accerating upwards of 2m/s^{2}, Find the balance reading.(3mks)
 State kinetic theory of matter. (1mk)
 State the condition for total internal reflection to occur. (2mks)

 A figure below shows a car decelerating uniformly from a velocity of 10m/s to rest in 2s.
If it takes 2s to reverse with uniform acceleration to its original starting point, determine the: displacement of the car 2mkS
 average velocity of the car (3marks)
 distance travelled by the car (3marks)
 average speed of the car (2marks)
 An object is placed 30cm from a concave mirror of focal length 20cm. Calculate the magnification. (3mks)
Explain why it is dangerous for a bus to carry standing passengers. (2mks) 
 A uniform metro rule is balanced at the centre of gravity by a force 30N, 5N and the magnetic force between P, and Q. P is fixed and Q has a weight
Ignoring the weight of the metre rule, calculate the value of the magnetic force between Q and P. (3mks)  Given that the lower end of Q is Northpole, state the polarity of the end of P facing Q (1mk)
 A uniform metro rule is balanced at the centre of gravity by a force 30N, 5N and the magnetic force between P, and Q. P is fixed and Q has a weight

 Give a reason why water is not suitable as a barometric liquid. (1mk)
 Explain why a lift pump is unable to raise water from a borehole where the level of water is 20M below the ground level. (2mks)
 State two reasons why gases diffuse faster than solids. (2mks)
 The diagram below shows a ray of light travelling between waterglass interfaces.
Calculate the value of I given that ang=1.52, and a^{n}w=4/3 (3mks)
MARKING SCHEME
INSTRUCTIONS
ANSWER ALL QUESTIONS IN THE SPACE PROVIDED.
 30cm^{3} of petrol is mixed with 40cm^{3} of kerosene. If the density of petrol is 0.70gcm^{3 }and kerosene is 0.80gcm^{3}. Calculate the density of the mixture. (3mks)
Density= total mass = pp x vp+pkxvk
Total volume Vp+Vk
= (0.07x 30+0.08x40)g
(30+40)cm^{3}= (21+32) g
70cm^{3}
0.76gcm^{3}  60 drops of water are transferred to a beaker from a burette. The level of water in the burette fall from 17cm^{3} mark to 20cm^{3} mark. Calculate the volume of I drop of water (3mks)
Volume of 60 drops= (2017)cm^{3} = 3cm^{3}
Volume of a drop = (^{3}/_{60}) cm^{3}
=0.05cm^{3}  Name the forces acting on
 A box resting on a bench
Reaction force  Between the wheels of a moving car and the road
Friction force  On an object immersed in water
Up thrust force  Between n pole and spole of a magnet
Magnetic force  Between water poured on glass and the glass surface.
Adhesion force
 A box resting on a bench

 State two practical applications of friction force in our daily lives. (3mks)
Walking
braking  List three ways in which friction force can be reduced. (3mks)
polishing the surface
lubricating
use of ball bearing
 State two practical applications of friction force in our daily lives. (3mks)
 The figure below shows a form of a hydraulic lift.
Using Pascal’s principle, determine the forces F2 on the small piston to lift the load. (4mks)
F1 = F2 = 100 = F2
A1 A2 0.25 10
F2= 100 x 10 = 4,000N
0.25  Study the setup below and answer the questions that follows
 What observation would be made in the tube after some time. (1mk).
A white ring forms in the tube  Indicate in the diagram the likely position where the observation stated in (a) above would take place. (1mk)
 What observation would be made in the tube after some time. (1mk).

 when taking care of a lead acid accumulator, what must be done if the
 Density of the acid becomes too low. (1mk)
Recharge the battery  Level of the acid becomes too low. (1mk)
Top up using distilled water
 Density of the acid becomes too low. (1mk)
 An echo sound sends sound signals to the bottom of a lake and receives them back after 0.08s. Find the depth of the lake. (Take the speed of sound in water 1400m/s) (2mks)
D= 1⁄2vt=1⁄2 x 1400 x 0.08
=56m
 when taking care of a lead acid accumulator, what must be done if the
 The velocity of light in water is 2.2 x 10^{8}ms and the velocity of light in a diamond is 1.24 x.10^{8}m/s. Calculate
 Retractive index of light passing from water to diamond. (3mks)
Wnd = vol of light in water
Vol of light no diamond
= 2.2x10 ^{8}
1.24 x 10^{8}
=1.774  The critical angle for water is 48.6º. Calculate the refractive index of water. (2mks)
N=1⁄_{sinc}
=1⁄_{48.6º}
1⁄_{0.}_{7501}1.53  State the applications of total internal reflections.
Penscope
prism binoculars
Pentaprism
Optical fibre
 Retractive index of light passing from water to diamond. (3mks)
 Some smoke was enclosed in a smoke cell and observed under a microscope as shown in figure 2. State and explain the observed motion of the smoke particles. (2mks)
Smoke particles were observed to move in short, random and zigzag paths. ;
This was due to bombardment by air molecules.  The figure below shows samples of the same liquid B and C being heated through a well – lagged copper rod of nonuniform crosssectional area. A thermometer is placed in each sample for some time. .
If the rod is being heated at the middle, state an explain which thermometer record higher temperature. (2mks) Thermometer in the sample B
 The rate of conductivity of heat increases with crosssectional area
 The figure below shows a Bunsen – burner.
Use the Bernoulli’s principle to explain how air is drawn into the burner when the gas tap is opened. (3mks) As the gas passes through the nozzle, the velocity increases thus
 The pressure decrease above the nozzle
 The higher atmosphere pressure pushes the air into a gas stream
 Using a well labeled diagrams, show three states of equilibrium. 3mks
 State and explain the type of equilibrium the marble is in (2mks)
 Ustable
 Any push causes the marble to roll so as to lower the position of C.O.G
 Define the moment of a force. (1mk)
The product of force and the perpendicular distance from the line of action of force to the turning point. (pivot)
 State and explain the type of equilibrium the marble is in (2mks)

 What is a luminar flow? (1mk)
It is the streamline flow with the particles of fluid moving in layers.  State two assumptions needed in derivation of equation of continuity. (2mks)
The fluid must be incompressible
The fluid must be nonviscous
The liquid should have a steady flow  State two effects of Bernoulli’s principle. (2mks)
Lifting effect
Blowing roof tops
Bunsen burner
Road accidents
Spray gun
 What is a luminar flow? (1mk)

 State Newton’s first law of motion. (1mk)
A body in a state of rest remains at rest and if moving continues moving in a straight line unless acted upon by external forces.  Give a reason why it is important that passenger’s in moving vehicles put on safety belts. (2mks)
in case of emergency breaking of collition, they are held/trapped on their seats.
this prevents injuries
 State Newton’s first law of motion. (1mk)

 A boy of mass 60kg stands on a balance in a lift which is accerating upwards of 2m/s^{2}, Find the balance reading. (3mks)
Reaction ( R) = M(ga)
=60(10x2)
=720  State kinetic theory of matter. (1mk)
States that matter is made up of tiny particles which are in random motion  State the condition for total internal reflection to occur. (2mks)
Incident angle should be greater than article angle
The light rays should transverse from optically denser medium to less denser medium
 A boy of mass 60kg stands on a balance in a lift which is accerating upwards of 2m/s^{2}, Find the balance reading. (3mks)
 A figure below shows a car decelerating uniformly from a velocity of 10m/s to rest in 2s.
If it takes 2s to reverse with uniform acceleration to its original starting point, determine the: displacement of the car 2mks
½ x 2x (+10) + ½ x 2(10)
= (+10  10)
=0  average velocity of the car (3marks)
average velocity = displacement
time
=0/4
=0m/s  distance travelled by the car (3marks)
area = ½ x 2 x 10 + ½ x 2 x 10
10 + 10 = 20m  average speed of the car (2marks)
av. Speed = (distance travelled)
time taken
20/40 = 0.5m/s
 displacement of the car 2mks
 An object is placed 30cm from a concave mirror of focal length 20cm. Calculate the magnification. (3mks)
F=t20 V=+30
1/f=1/v+1/v, 1/v, 1/v=1/f+1/u
=1/21/30
1/v= 32= 1
60 60
V=+60cm
M=v/u= 60
30
= 2 Explain why it is dangerous for a bus to carry standing passengers. (2mks)
The centre of gravity (cog) is raised
This makes the bus unstable (likely topple)
 Explain why it is dangerous for a bus to carry standing passengers. (2mks)
 A uniform metro rule is balanced at the centre of gravity by a force 30N, 5N and the magnetic force between P, and Q. P is fixed and Q has a weight

 Ignoring the weight of the metre rule, calculate the value of the magnetic force between Q and P. (3mks)
Σ Acm= Σcm
3vx20=20xf
F=600
30
=20N
Magnetic force
=(205)
=15N  Given that the lower end of Q is Northpole, state the polarity of the end of P facing Q (1mk)
South pole
 Ignoring the weight of the metre rule, calculate the value of the magnetic force between Q and P. (3mks)

 Give a reason why water is not suitable as a barometric liquid. (1mk)
It has low density hence need a long column of water to support atmospheric pressure  Explain why a lift pump is unable to raise water from a borehole where the level of water is 20M below the ground level. (2mks)
The maximum height con be raised is 10M . Reason. The pump operates due to atmospheric pressure
Reason: The pump operates due to atmospheric pressure  State two reasons why gases diffuse faster than solids. (2mks)
Gas particles are light and diffuse faster
Solid particles are held together
 Give a reason why water is not suitable as a barometric liquid. (1mk)
 The diagram below shows a ray of light travelling between waterglass interfaces.
Calculate the value of I given that ang=1.52, and anw=4/3 (3mks)
N1 sin ϴ1=n2 sin ϴ_{2}
43 sin i=1.52 sin 28º
Sin I = ¾ x 1.52 sin 28
I=32.60
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