A force of 20 N displaces a body by a distance of 4 m. Find the amount of work done when the displacement is:

(a) in the direction of force.

(b) at an angle of 60° with the force.

(a) Name the two major parts of a SONAR.

(b) Name the type of vibrations produced in the given case: A freely suspended pendulum vibrating about its mean position.

(a) Name the colour code of wire which is connected to the metallic body of an appliance according to the new convention.

(b) Which part of electrical appliance is earthed?

Calculate the mass of ice required to lower the temperature of 600 g of water at 50°C to water at 12°C. (Take, specific latent heat of ice = 366 Jg^-1 and specific heat capacity of water = 4.2 Jg^-1°C^-1)