Name. School Index No.. Candidate s sign. Date. 232/1 PHYSICS Paper 1 THEORY July/August 2010 2 Hours BORABU - MASABA NORTH DISTRICTS JOINT EVALUATION TEST - 2010 Kenya Certificate of Secondary Education (K.C.S.E) PHYSICS Paper 1 July/August 2010 2 Hours Instructions to candidates 1. Write your name, index number, school and date in the spaces provided above 2. Sign and write the date of the examination in the spaces provided above 3. This paper consists of two sections: A and B. 4. Answer all the questions in the spaces provided 5. All writing must be clearly shown in the spaces provided 6. Non programmable silent electronic calculators and KNEC mathematical table may be used. Take acceleration due to gravity g = 10 ms 2 Take π = 3.142 FOR EXAMINER S USE ONLY SECTION QUESTION MAXIMUM SCORE CANDIDATES SCORE A 1-14 25 15 12 16 10 B 17 08 18 10 19 15 TOTAL 80 This paper consists of 12 printed pages. Candidates should check the question paper to Ensure that all the pages are printed as indicated and no questions are missing. SECTION A (25 marks) 1
1. Ten glass marbles, each of mass 6.0 g, were gently lowered into a 100cm 3 measuring cylinder containing water to the level marked A. The water level rose to the level marked B as shown in Fig. 1 below Determine the density of the glass. (3mks).. 2. On the axes provided, sketch a graph of PV against V for ideal gas in which Boyle s law is obeyed. (1mk) 3. Fig. 2 represents a flaming non-drip candle. State and explain how the candle s stability changes as it burns.. 2
4. Water flows steadily through a pipe of diameter 30 mm at 20 ms -1. The pipes narrows at some point and its diameter reduces to 20 mm. what is the speed of water at this point? (3mks)... 5. Fig.3 below shows a stretched spring held in position by two identical spring balances P and Q. What will be the reading on spring balance Q? (1mk). 6. Two identical cans A and B are suspended from a horizontal support with strings of the same length as shown in Fig.4.Can A is empty while B is full of paint. They are both displaced simultaneously and left to swing freely. Which can is likely to remain swinging for a longer time? Explain.. 3
. 7. Name one state of matter in which Brownian motion occurs. (1mk). 8. A metal pail feels colder to touch than a plastic pail on a cold morning even though both have the same temperature. Explain this observation.. 9. State one assumption made when estimating the size of an oil molecule in the oil drop experiment. (1mk). 10. A lady of mass 80 kg walks up a flight of 10 stairs each 20 cm high in 5 seconds. Determine the power she develops. (3mks).. 11. If a tent is touched with a finger on inner surface, when it is raining, it allows the rain water to leak through. Give a reason for this observation. (1mk). 12. Explain how a person is able to drink a soda using a drinking straw.. 4
13. State two factors which determine the maximum speed at which a car can successfully negotiate a corner on a banked road.. 14. Fig.5 shows a load-extension graph for various loads hang from a single spring. On the same axes sketch a load-extension graph for various load hang from two parallel springs which are identical to the single spring. (1mk) 5
SECTION B (55 MARKS) 15. The data provided in table 1 shows the variation of displacement covered, by a train accelerating uniformly along a straight rail track, with time. Table 1 Time(s) 0 10 20 30 40 50 60 70 Displacement(m) 22.5 40.0 62.5 90.0 122.5 160.0 202.5 250.0 (a) On the grid provided, plot a graph of displacement (y axis) against time (5mks) 6
(b) From the graph determine: (i) The velocity at the 25th second (3mks)... (ii) The velocity at the 55th second.. (iii) The acceleration of the train (3mks)... 16. (a) Fig 6 below shows a uniform plank of weight 20N and length 1.0m balanced by a 0.5kg mass at a distance x from the pivot point O. Figure 6 Determine the value of x (3mks)....... 7
(b) When the block is completely immersed in water the pivot 0 must shift by 0.05 m to the left for the system to balance. The density of water is 1000 kgm -3.Determine: (i) The upthrust U on the block. (4mks)..... (ii) The volume of the block. (3mks)....... 17. (a) A trolley is moving with uniform velocity on a friction compensated track. When a piece of plasticine is dropped on the trolley, the velocity of the trolley decreases. Explain this observation..... (b) The graph in Fig. 7 shows the variation of velocity with time for a bullet of mass 20g moving through the trunk of a tree until it comes out on the other side. 8
Determine: (i) The diameter of the tree trunk.. (ii) The change of momentum of the bullet.. (iii) The retarding force on the bullet.. 18. (a) Fig. 8 shows a cylindrical can filled with a liquid of density 0.8 gcm -3. A hole of diameter 2.0 cm is drilled at a depth of 2.8 m from the top of the can. Determine: (i) The cross-sectional area of the hole.... 9
(ii) The maximum pressure exerted by the liquid at the hole.... (iii) The maximum force exerted on a jet of liquid through the hole.... (b) A stone of mass 0.2 kg tied to a string is whirled in a horizontal circle of radius 1.0 m at a constant speed of 3.0 ms -1. Determine: (i) The angular velocity of the stone.... (ii) The tension in the string.... (iii) The number of revolutions the stone makes in one minute... 10
19. (a) You are provided with the following apparatus: A filter funnel, a thermometer, a stop watch, ice at 0 C, an immersion heater rated P watts, a beaker, a stand, boss and clamp and a weighing machine. Describe an experiment to determine the specific latent heat of fusion of ice. Clearly state the measurements to be made. (4mks)... (b) 200 g of ice at 0 C is added to 400g water in a well lagged calorimeter of mass 40g. The initial temperature of the water was 40 C. If the final temperature of the mixture is X C, (Specific latent of fusion of ice L = 3.36 x 10 5 Jkg -1, specific heat capacity of water, c = 4200Jkg -1 K -1, specific heat capacity of copper = 400 Jkg -1 K -1.) (i) Derive an expression for the amount of heat gained by ice to melt it and raise its temperature to X C... (ii) Derive an expression for the amount of heat lost by the calorimeter and its content when their temperature falls to X C.... 11
(iii) Determine the value of X. (3mks).. (c) A hydrogen balloon of volume 1.2 m 3 is released at the ground level where the pressure is 680 mmhg and a temperature of 20 C. Determine the volume of the balloon at a height of 2500m above the ground where the pressure drops to 500 mmhg and the temperature is 4 C. (4mks)... 12 END