A stone projected horizontally from the top of a tower with a speed of 4 ms\(^{-1}\) lands on the level ground at a horizontal distance of 25 m from the foot of the tower. Calculate the height of the tower. = 10 ms\(^{-2}\)]

(a) Explain diffusion.

(b) Give one reason why the rate of diffusion is higher in gases than in liquids at the same temperature.

State: (a) the difference between plane polarized light and ordinary light;

(b) two uses of polaroids.

(a). State: (a) two applications of electrolysis in an industry

(b) one application of electrolysis in a school laboratory.

In fig. la and fig.1 b above, Ida and Wb represent the respective loads on a spring placedtiear a 30 cm rule, when in air and when in water:

(a) Identify the force causing a shrink in the spring in fig.(b).

(b) Given that the force constant of the spring is 2.0 x 10\(^{11}\) Nm\(^{-1}\), calculate the work done by the force in causing the shrink.