Siaya District Secondary Schools Evaluation Examinations - 2017

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232/1

PHYSICS

Paper 1

Time: 2 Hours

SIAYA DISTRICT SECONDARY SCHOOLS EVALUATION EXAMINATIONS - 2017

Kenya Certificate of Secondary Education (K.C.S.E)

232/1

PHYSICS

Paper 1

May/June 2017

Time: 2 Hours

INSTRUCTION TO CANDIDATES

This paper consists of TWO sections A and B.
Answer ALL Questions in the spaces provided.
ALL workings MUST be clearly shown
Mathematical tables and electronic calculators may be used.

For Examiner’s Use only

SECTION / QUESTION / MAXIMUM SCORE / CANDIDATE’S SCORE
A / 1-8 / 25
B / 9 / 15
10 / 14
11 / 11
12 / 15
TOTAL SCORE / 80

This paper consists of 12 printed pages.

Candidates should check the question paper to ensure that all pages are printed as indicated

and no questions are missing

SECTION A ( 25 Marks)

Answer ALL questions in this section in the spaces provided

1.Jupiter’s gravitational field strength is 26N/kg what would be the weight of an object that weighs 30N on earth on Jupiter. (Take g=10N/Kg on earth) (3mks)

2.An alloy contains 40% by mass of lead and 60% by mass of tin. Determine the density of the alloy in kgm3. (density of lead = 11.4g/cm3 and density of tin = 7.3g/cm3) (3mks)

3.In the figure below, a strong, round bottomed flask is fitted with a two-holed rubber bung through which passes a thermometer and a short glass tube. The glass tube is then connected to a suction pump (filter pump)

(i) State two observations that would be made after sometime.(2mks)

(ii) Briefly explain your observation.(2mks)

4.The figure below shows a liquid in a long cylindrical tube closed at one end with a cork. The cork is tight fitting but movable. The system is in equilibrium.

(i) State two observations that would be made when the tube is gently heated uniformly. (2mks)

(ii) Briefly explain your observation.(2mks)

5.Two stones of equal masses are hung as shown below. One hangs from an inextensible thread while the other hangs from an inextensible thread tied to a light spring as shown below. When the two masses are raised to the same height and suddenly dropped, thread A breaks while B does not. Explain. (3mks)

6.A box of mass 300kg is pulled along an inclined plane by a force of 2000N as shown below.

Determine the efficiency of the inclined plane.(3mks)

7.A crystal of potassium permanganate was placed in a corner at the bottom of a glass beaker filled with water and the beaker heated at that corner. The figure below shows the observation made during the heating process. Briefly explain this observation. (3mks)

8.Determine the power of a freezer which can convert water of mass 400g from 95oC to ice at

-200C in 3.5 hours.

(Specific heat capacity of water =4200J/kgk

Specific heat capacity of ice = 2100J/kgk

Specific latent heat of fusion of ice = 3.36x105J/kg)(2mks)

SECTION B (55MARKS)

Answer ALL questions in the spaces provided

9.The figure below shows a cross-section of a cylinder, fitted with two pistons, A (area 1cm2) and B (area = 10cm2), containing an incompressible liquid. The wider end encloses a fixed mass of gas, initially at a pressure of 105N/m2. If a mass of 4kg is placed on piston A.

a) Assuming that both pistons are of negligible weight, calculate

(i) The total force acting on the enclosed gas.(3mks)

(ii) The pressure of the enclosed air in the cylinder.(3mks)

b) Varying masses, m, are placed on piston A and corresponding lengths ,L, of the column of the enclosed air noted. The results obtained are as shown in the table below. (Assume the temperature remains constant throughout the experiment)

Mass m (Kg) / 1 / 2 / 3 / 4 / 5 / 6
Length L (cm) / 5.0 / 3.3 / 2.5 / 2.0 / 1.7 / 1.4
I/L (cm-1)

(i) Complete the table of values for I/L(2mks)

(ii) On the grid provided, plot a graph of I/L(y axis) against m.(5mks)

(iii) From your graph, determine the volume of the enclosed air when no mass is placed on the piston. (2mks)

10.(a) (i) State Newton’s first law of motion.(1mk)

(ii) A bus of mass 5,000kg and a car of mass 1200kg are both traveling on a dual carriage way at the same velocity. If both drivers apply the same breaking force, state with reason which one will come to stop first. (2mks)

b) (i) The driver of the car (mass 1200kg), traveling at 72kmh-1 notices an object lying on the road 42 metres away and applies a breaking force of 6000N. Determine, by calculation, whether or not the car will hit the object. (3mks)

(ii) Two objects A and B of the same mass were dropped from the same height. Object A landed on a foam mattress while B landed on a concrete floor. Below are graphs of force against time measured for the two objects at the time of impact.

(i) State which one of the object had a higher force of impact.(1mk)

(ii) What doesthe area under each curve represent.(1mk)

c) A tape attached to a moving trolley is run through a ticker-timer, producing a tape as shown below.

If the frequency of ticker-time is 50Hz.

Calculate:

(i) The average velocity of the trolley at intervals AB and CD.(4mks)

(ii) The average acceleration of the trolley.(2mks)

11.a) The diagram below shows two stationary trolleys A and B separated by a compressed spring and held together by inextensible thread. The mass of trolley A is 2.0kg and the mass of trolley B is 0.1kg. When the thread is cut, the trolleys move rapidly apart.

(i) State the energy changes that occur when the string is cut.(1mark)

(ii) If trolley A moves off with a speed of 0.25ms-1. Calculate the speed with which trolley B moves off. (4mks)

b) A steel ball of mass 0.10kg was placed on top of a level ground. The spring was then compressed by 0.20m with an average force of 10N.

(i) State the energy changes that take place when the compressed spring is released and the steel ball moves to its maximum height. (2mks)

(ii) Calculate the maximum height the ball attains (Take g=10Nkg-1)(4mks)

12.A fishing boat, 40 metres long and 8 metres wide floats partially submerged in water. If fish weighing 125,000N is added into the boat. (Density of water=1000kg/m3)

Determine:

a) (i) The mass of extra water displaced.(2mks)

(ii) Increase in volume of water displaced.(2mks)

(iii) The distance the boat sinks into the water.(2mks)

b) The figure below shows a metal sphere of mass 500kg and volume 0.8m3 fully submerged in sea water of density 1030kgm-3. Use the information above to determine:

(i) the weight of water displaced.(2mks)

(ii) the tension in the cable.(T)(2mks)

(ii) Mark and name on the diagram in 12(b) above, two other forces, apart from tension T. (2mks)