- What is the reading of the vernier eallipers shown in the fly below if it has a positive error of 0.02cm? (3mks)
- The figure below shows apparatus used to observe behavior of smoke particles in a smoke cell.
- State a reason why smoke particles are used in the experiment. (1mk)
- State the observation made. (1mk)
- What would happen if temperature was lowered? (1mk)
- Explain why fish can survive under water when the surface is already frozen. (1mk)
- State one way on which the stability of the can be increased. (1mk)
- A stone is thrown horizontally from a building that is 50m high above a horizontal ground. The stone hits the ground at a point, which is 65m from the foot of the building. Calculate the initial horizontal velocity of the stone. (g=10ms-2) (3mks)
- The figure below shows air flowing through a pipe of non-uniform cross-sectional area .Two pipes A and B are dipped into liquids as shown below.
- Indicate the levels of the liquids in pipe A and B. (1mk)
- Explain your answer in (a) above. (1mk)
- When a mercury thermometer is used to measure the temperature of hot water, it is observed that the mercury level first drops before beginning to rise. Explain (2mks)
- Figure below shows a u-tube manometer containing a liquid L. One end connectected to a gas tap.
Given that the atmosphere pressure is 1.0×105pa, determinate the pressure of the gas (density of liquid L is 900kg/m3, g=10N/kg) (2mks) - The figure below represents part of a tape pulled through a ticker-timer by trolley moving down an inclined plane. If the frequency of the ticker-timer is 50Hz, calculate the acceleration of the trolley. (3mks)
- Explain why a glass container with thick glass walls is more likely to crack than one with a thin wall when a very hot liquid is poured into it. (2mks)
- Find the amount of work in stretching a sprig constant 25N/M when its lenghth is increased from 0.1m to 0.2m. (3mks)
SECTION B (55MARKS)
-
- Define specific latent heat of fusion of a substance. (1mk)
- Water of mass 200g at a temperature of 60ºc is put in a well lagged copper calorimeter of mass of 80g. A piece of ice at 0ºc and mass 20g is placed in the calorimeter and the mixture stirred gently until all the ice melts. The final temperatures, T of the mixture are then measured. Determine:
- The heat absorbed by melting ice at 0ºc. (2mk)
- The heat absorbed by melted ice (water) to rise to temperature. T (Give the answer in terms of T (2mks)
- The heat lost by warm water and the calorimeter. (2mks) (Give the answer interms of T)
- The heat lost by warm and the calorimeter (2mks) (Give the interms of T)
- The final temperature T of the mixture. (Specific latent heat of fusion of ice=334,000 Jkg-specific heat of water =4200Jkg-1, specific heat capacity of copper =900Jkg-1k-) (3mks)
- A ball bearing x is dropped vertically downwards from the edge of the table and it takes 0.5s to hit the floor below. Another ball bearing Y leaves the odge of the table horizontally with a velocity of 5ms-1 find :
- The horizontal distance travelled by Y before hitting the floor. (2mks)
- The vertical distance of the table top above the floor level. (2mks)
- A bullet mass of 22g travelling horizontal with a velocity of 300ms-1 strikes a block of wood of mass 1978g which rests on a rough horizontal surface. After impact the bullet and the block move together and come to rest when the block has travelled a distance of 5M. Calculate :
- The velocity of bullet and wood after impact. (2mk)
- The force of friction between wood and surface. (2mks)
- A car starts from rest and accelerates uniformly at 2m/s2 for 5 seconds before accelerating again at 2.5 m/s2 for 2 more seconds. The car is then brought to rest in another 2 seconds.
- Sketch a velocity time graph for this motion. (2mks)
- From the graph, calculate the total distance travelled. (2mks)
-
- State two important factors to be considered when selecting the banking angles of a road.
- A ball of mass 2kg is whirled at the end of a string in a horizontal circular path at a speed of 5m/s-1. If the string is 2.0m long find,
- Angular velocity of the stone? (3mks)
- The tension of the string.
- The figure below shows a block of mass 30.0kg being pulled up a slope by a force F at a constant speed. The friction force on the block is 200 N.
-
- on the same figure above name and indicate the other forces acting on the block. (2mks)
- Determine the force acting on the block down the slopes. (2mks)
- Determine the value of F (2mks)
- On reaching the top of the slopes. The block is left to run freely down the slopes.
- Which of the force previously acting on the block would then act in the opposite direction? (1mk)
- Determine the acceleration of the block down the slope. (2mks)
- What is the effect of increasing the angle of the slopes on your answer in (ii) above? (1mk)
-
-
-
- State Newton’s second law of motion. (1mk)
- The figure below shows a sphere moving in a viscous liquid in a tall measuring cylinder.
Show on the diagram the force acting on the sphere. (3mks) - Sketch on the Cartesian plane below a graph of the variation of velocity with time until the ball attains terminal velocity.
-
- State Boyle’s law. (1mk)
- What is the absolute zero temperature? (1mk)
- A bicycle pump with the exit hole closed contains 80cm of air at 760 mmHg pressure and a temperature of 10c. When the air was compressed to 38cm under a pressure of 1700mmHg pressure, its temperature rises. Calculate the rise in temperature. (2mks)
-
MARKING SCHEME
- Main scale reading=6.7
V scale reading=0.6
6.7+0.6=6.76
Correct reading =6.76-0.02
=6.74cm -
- Smoke particles are lighter than air particles and big enough to be seen.
- The smoke particles are observed to be in continuous random motion.
- The rate of continuous motion reduces due to decrease in k.e.
- Water at 4ºc is denser; it is also poor conductor of heat.
-
- Increase base area
- Lower C.O.G
- H=1/2gt2
-
- The liquid level is high in pipe B than in pipe A because is low deu to the high speed of the air.
- The bulb gets heated first and expands creating more volume.
- The mercury then gets heated and expands.
- Gas pressure=pa +hpg
=1.0×105+ (900×10×0.06)
=10, 000+540
=100,540 pa - T=1/50=0.02 sec
U=0.06 =30cm/s
0.02
V= 2.6 =130cm/s
0.02
A=v-u= 130-30
t (7×0.02)
= 100
0.14
=714.29cm/s2 - For a thick glass, the inner wall expands more than the outer wall because glass is a poor conductor, while in a thinner one, the expansion is uniform.
- W=1/2ke2
=1/2 ×25× (0.1)2
=1/2 ×25× 0.01
=0.125J
SECTION B
-
- Specific latent heat of fusion a substance required to melt completely one kilogram of a substance to liquid without change in temperature.
-
- Q=ML
=0.02×334,000J
=6680J - Q=Mcd0
=0.02×4200 (t-0)
=84T J - Heat lost by warm water
=mcDo
=0.2×4200 (60-T)
Heat lost by colollmeter
=mcDo
=0.08 ×900 (600T) - Heat gained=Heat lost
6680+84T=0.2 ×4200 (60-T) +0.08×900 (60-T)
6680 +84T =50,400 + 4320 -72T
996T =48040
T= 48.2ºC
- Q=ML
-
- R=ut =5×0.5
=2.5ms-1 - S=ut+1/2gt2
u=0
S= 1/2×10× (0.5)2
=5×0.25
=1-25m - m1u1+m2u2= (m1+m2)v
(0.022×300) = (0.022 +1.978) v
6.6=2/2v
V=3.3ms-1 -
- 1/2×5×10=25
3×10=30
(15+10)×1/2×2=50
1/2×2×15=15
25+30+50+15=120m
- R=ut =5×0.5
-
- Radius of the curve.
Critical speed. -
- W=v/r
=5/2
=2.5rads-1 - T=Fc= mv2
r
= 2×5 2
2
= 0.625=0.3125N
2
= 0.3125N
- W=v/r
- Radius of the curve.
-
-
- F=mgsin0
=30×10sin 10
=52.1N ±0.02 - F=Total force down
=mg sin 0 +friction force
=52.1N + 20.0N
=72.1N
-
- Friction force
- Net force down =mg sin –friction force
=52.1 -20
=32.1
But F=ma
A=f/m=32.1=1.07ms-2
30 - Acceleration downwards increases with increase in angle
-
-
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- The rate of change of momentum of the body is directly proportional to the applied force and takes place in the direction of force.
-
- For a fixed mass of a gas pressure is inversely proportional to the volume at constant temperature.
- Temperature at which the gas molecules have zero internal energy.
- P1V1=P2V2
T2 T2
760×80 =1700×38
283 T2
T2=1700×38×283
760×80
=300.68
Temp rise =300.68-283 =17.69k
17.69k
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