Power of Avinash PA = F A .v A = 10 x 8 = 80 W Power of Kapil PK . FK . vK = 25 x 3 = 75…
Initial velocity = v, then final velocity, v’ = 3v Initial kinetic energy = Final kinetic energy (KE) = mv’2 = 2 = 9 (KE) initial: (KE) final = 1…
Suppose a body of mass m is moving with velocity v. It is brought to rest by applying a retarding force F. Suppose it traverses a distance s before coming…
(i) Electric heater: Electric energy into heat energy. (ii) Solar battery: Solar energy into electric energy. (iii) Dynamo: Mechanical energy into electric energy. (iv) Steam engine: Heat energy to mechanical…
Three examples when force being supplied and still there is no displacement are: (i) A man pushing a stationary truck. (ii) A man pushing a rigid wall. (iii) A boy…
Work done in diagram I = mgh. Work done in diagram II = mgh. Work done by gravity depends on the differences in vertical heights of the initial and final…
Power is the rate of doing work. Kilowatt is the unit of power and kilowatt hour is the unit of energy.
Suppose a body of mass m is lifted vertically upwards through a distance h. In this case, the force required to lift the body will be equal to weight of…
We know that, 1kWh = 1kW x 1 h = 1000 W x 3600 s = 1000 Js-1 x 3600 s = 3600000 J ∴ 1kWh = 3.6 x 106…
The commercial unit of energy is kilowatt hour [kWh]. 1 kWh is the energy used in one hour at the rate of 1000 Js-1 .