Question Library

The horizontal component of the initial speed of a particle projected at 30^\circ to the horizontal is 50 m\(^{-1}\). If the acceleration of free fall due to gravity is 10 ms\(^{-2}\), determine its; (a) initial speed; (b) speed at the maximum height reached.

A ball bearing falls through a viscous liquid (a) Using a labelled diagram of a tall vessel, show all the forces acting on it (b) When will it attain terminal velocity?

An electron of charge 1.60 x 10\(^{-19}\)C is accelerated under a potential difference of 1.0 x 10\(^{5}\) V. Calculate the energy of the electron in joules.

a) On what principle does lighting in a fluorescent tube operate? (b) State two factors which determine the colour of light produced in a fluorescent tube.

(a) State Heisenberg's Uncertainty Principle. (b) State one phenomenon that can only be explained in terms of the wave nature of light.

(a) A particle moves on a straight path with an initial speed u and final speed v in time t. Show that the total distance X covered by the particle is given by \(x = ut + \frac{1}{2}at^2\) where a is the magnitude of acceleration (b) State; (i) Newton's second law of motion (ii) the principle of conservation of energy (iii) the law of floatation. (c) Consider a balloon of mass 0.030 kg being inflated with a gas of density 0.54 kg m\(^{-3}\). What will be the volume of the balloon when it just begins to rise in air of density 1.29 kg m\(^{-3}\)? [ g = 10 ms\(^{-2}\)]

(a) State two differences between boiling and evaporation. (b) A closed inexpansibie vessel contains air saturated with water vapour at 77^\circC. The total pressure in the vessel is 1007 mmHg. Calculate the new pressure in the vessel if the temperature is reduced 1.2 27^\circC. [ The s.v.p. of water at 77^\circC and 27^\circC respectively are 314 mmHg and 27 mmHg. Treat the air in the vessel as an ideal gas] (c) The lengtn of a zinc rod at 23^\circC is 200 m. Calculate the increase in length of the rod when its temperature rises to 33^\circC. [ expansivity of zinc = 2.6 x 10\(^{-5}\) K\(^{-1}\)] (d) Explain with there is no temperature change when a solid being heated changes into liquid at its melting point.

(a) What is a magnetic field? (b) With the aid of a labelled diagram describe an experiment to show that a magnetic field exists around a straight wire carrying current. (c) A 40 \(\mu\)F capacitor in series with a 40 Q resistor is connected to a 100 V, 50 Hz a.c. supply. (i) Draw a circuit diagram of the arrangement (ii) Calculate the: I. impedance in the circuit; II. current in the circuit III. potential difference across the capacitor.

(a)(i) State Einstein's equation of photoelectric effect (ii) What conservation principle does the equation represent? (b) List three applications of photocells (c) A photo emissive surface has a threshold frequency of 4.02 x 10\(^{14}\)Hz. If the surface is illuminated by light of frequency 5.0 x 10\(^{15}\)Hz, calculate the: (i) threshold wavelength; (ii) work function; (iii) kinetic energy of the emitted photoelectrons. [ c = 3.0 x 10\(^{8}\) ms\(^{-1}\), h = 6.63 x 10\(^{-34}\) Js]

You are provided with a uniform meter rule, a knife edge, masses and other necessary apparatus. Suspend the metre rule horizontally on the knife edge. Read and record the point of balance G of the métre rule. Keep the knife edge at this point throughout the experiment. Using the thread provided, suspend the object labelled W at the 15cm mark of the metre rule. Suspend a mass M= 20g on the other side of G. Adjust the position of the mass until the metre rule balances horizontally again. Read and record the position Y of the mass M on the metre rule. Determine and record the distance L between the mass and G. Also determine and record the distance D between W and G. Repeat the procedure for four other values of M = 30, 40, 50 and 60 g. In each casse ensure that W is kept Constant at the 15 cm mark and the knife edge at G. Evaluate L\(^{-1}\) in each case. Tabulate your readings. Plot a graph of M on the vertical axis against L\(^{-1}\) on the horizontal axis. Determine the slope S, of the graph. Evaluate \(\frac{4}{D}\) State two precautions taken to obtain accurate results. (b)i. State the principle of moments. ii. Define centre of gravity

A gramophone record takes 5s to reach its constant angular velocity of 4\(\pi\) rads-1 from rest. Find its constant angular acceleration.

A car of mass 1500 kg goes round a circular curve of radius 50m at a speed of 40 ms-1. The magnitude of the centripetal force on the car is ?

Two spheres of masses 5.0 kg and 10.0 kg are 0.3 m apart. Calculate the force of attraction between them? [G = 6.67 X 10-11 Nm2 Kg\(^{-2}\)]

A machine has a velocity ratio of 4. if it requires 800 N to overcome a load of 1600 N,what is the efficiency of the machine?

A reservoir 500 m deep is filled with a fluid of density 850 kgm-3. If the atmospheric pressure is 1.05 x 105 Nm-2, the pressure at the bottom of the reservoir is. [g = 10ms-2]