(a) Define Young's modulus

(b) When a force of 50 N is applied to the free end of an elastic cord, an extension of 4 cm is produced in the cord. Calculate the work done on the cord.

(a) List two properties of cathode rays

(b) Explain how the intensity and energy of cathode rays may be increased

  Give three observations in support of de Broglie's assumption that moving particles behave like waves.

(a) State two;

(i) properties of x-rays

(ii) reasons to show that x-rays are waves

(iii) uses of x-rays other than those in medicine;

(iv) hazards of x-rays.

(b) The potential difference between the cathode and target of an x-ray tube is 5.00 x 10\(^4\)V and the current in the tube is 2.00 x 10\(^{-2}\)A. Given that only one percent of the total energy supplied is emitted as x-radiation, determine the  ospheric pressure.

(i) maximum frequency of the emitted radiation

(ii) rate at which heat is removed from the target in order to keep it at steady temperature. [Planck's constant, h = 6.63 x 10\(^{-34}\) Js, electronic charge e = 1.60 x 10\(^{-19}\) C]

(a) Define gravitational field intensity

(b) In an experiment to determine the acceleration of free-fall due to gravity, g, using a simple pendulum of length I, six different values of I were used to obtain six corresponding values of period T. If a graph of I along the vertical axis is plotted against T\(^2\) on the horizontal axis;

(i) make a sketch to show the nature of the graph,

(ii) write down the equation that relates T, I and g hence obtain an expression for the slope of the graph

(iii) given that the slope of the graph is 0.25, determine the value for g [Take \(\pi\) = 3.142]

(c) A stone, thrown horizontally from the top of a vertical wall with a velocity of 15 ms\(^{-1}\), hits the horizontal ground at a point 45m from the base of the wall. Calculate the

(i) times of light of the stone

(ii) height of the wall [g = 10ms\(^{-2}\)]