Question Library

(a) State the conditions for the equilibrium of a rigid body acted upon by parallel forces (b)(i) Describe an experiment, using the principle of moments, to determine the mass of a metre rule (ii) State two precautions necessary to ensure accurate results. (c) A bullet of mass 120g is fired horizontally into a fixed wooden block with a speed of 20ms\(^{-1}\). The bullet is brought to rest in the block in 0.1s by a constant resistance. Calculate the: (i) magnitude of the resistance; (ii) distance moved by the bullet in the wood.

(a) Explain (i) work: (ii) power (b) Show that the efficiency E, the force ratio M.A. and the velocity ratio V.R. of a machine are related by the equation: E = M.A. x 100% V.R. (c) An inclined plane of angle 15^\circ is used raise a load of 4500N through a height of 2m. If the plane is 75% efficient calculate: (i) velocity ratio of the plane; (ii) work done on the load (d) Explain Charles' law using the Kinetic theory of matter.

(a) Sketch the magnetic flux pattern around a long; straight, current-carrying wire (b) State two methods by which the sensitivity of a moving-coil galvanometer can be increased. (c) A series RLC circuit comprises a 100-\(\Omega\) resistor, a 3-H inductor and a 4-\(\mu\)f capacitor. The a.c source of tile circuit has an e.m.f of 100V and a frequency of 160 Hz. (i) Draw the circuit diagram of the arrangement. Calculate the: (ii) capacitive reactance; (iii) inductive reactance: (iv) impedance of the circuit; (v) current in the circuit; (vi) average power dissipated in the circuit.

(a) Explain: (i) Fusion. (ii) Fission. (b) State three advantages of fusion over fission in the generation of power (c) Calculate in joules, the binding energy for \(\frac{59}{27}\) Co (Atomic mass of \(^{59}_{2} Co\) = 58.9332 u) (Mass of proton = 1.00783u) (Mass of neutron = 1.00867 u) (Unified atomic mass unit, U = 931 MeV) (1 eV = 1.6 x 10\(^{-19}\) J)

In the diagram, a thread AC, fixed at pulley A passes over pulley C on a force board and carries an unknown mass \(m_o\). Retain this mass \(m_o\) throughout the experiment. Draw a line along the direction of AC on the paper held behind the thread. Locate the mid-point B of AC and mark its position on this line. Draw BP at right angles to AC. By means of a loop of thread, suspend a mass M 50 g from AC and adjust the position of the loop so that the line of action of the weight of M lies along with BP. Ensure that M and \(m_o\), hang off the force board. Measure BO = y and AO. Evaluate y / AO. Repeat the experiment for M = 70,90,110 and 130g respectively. In each case, determine the corresponding values of y, AO, and y / AO. Tabulate your readings. Plot a graph of Y/AO on the vertical axis and M on the horizontal axis. Determine the slopes s of the graph. State two precautions taken to ensure accurate results. Attach your traces to your answer script. (b)i. Distinguish between the resultant and the equilibrant of forces. ii. State two conditions necessary for the equilibrium of three non-parallel coplanar forces.

A bullet fired at a wooden block of thickness 0.15m manages to penetrate the block. If the mass of the bullet is 0.025kg and the average resisting force of the wood is 7.5 x 103N, calculate the speed of the bullet just before it hits the wooden block.

The velocity of a sound wave at 27oC is 360ms-1. Its velocity at 127oC is

A ball is moving at 18ms\(^{-1}\) in a direction inclined at 60º to the horizontal. The horizontal component to its velocity is

A ball of mass 0.15kg is kicked against a rigid vertical wall with a horizontal velocity of 50ms-1. If it rebounced with a horizontal velocity of 30ms-1, Calculate the impulse of the ball on the ball · ·

The force of attraction between two point masses is 10-4N when the distance between them is 0.18m. If the distance is reduced to 0.06m, calculate the force.

A man whose mass is 80kg climbs a staircase in 20s and expends power of 120W. Find the height of the staircase.[g = 10ms-2]

A parachute attains a terminal velocity when

In a wheel and axle mechanism the diameters of the wheel and axle are 40cm and 8cm respectively. Given that the machine is 80% efficient, what effort is required to lift a load of 100N?

The tendon in a man's leg is 0.01m long. If a force of 5N stretches the tendon by 2.0 x 10-5m, calculate the strain on the muscle.

Which of these statements are correct for the pressures in liquids? i. pressure in a liquid at a point acts equally in all directions. ii. pressure increases with depth. iii. pressure at a depth depends on the shape of the container. iv. pressure at the same depth in different liquids are proportional to the density at different liquids.