A trolley is pushed along a road with a force of 400 N through a distance of 60 m in 1 minute. Calculate the power developed.

Name the devices or machines which convert:

(i) Electrical energy into sound energy.

(ii) Hear energy into kinetic energy (or mechanical energy).

(iii) Chemical energy into kinetic energy (or mechanical energy).

(iv) Chemical energy into heat energy.

(v) Light energy into heat energy.

Fill in the following blanks with suitable words:

(a) Power is the rate of doing ……….

(b) 1 watt is a rate of working of one ……… per ……..

(c) The electricity meter installed in our home measures electric energy in the units of ……..

(d) The principle of ………. Of energy says that energy can be ……. From one form to another, but it cannot be ……… or ….

(e) When a ball is thrown upwards, ……..energy is transformed into ……… energy.

What kind of energy transformations takes place at a hydroelectric power station?

What kind of energy transformations takes place at a coal-based thermal power station?