Advertisements
Advertisements
प्रश्न
State the law of conservation of energy.
Advertisements
उत्तर
According to the law of conservation of energy, energy can neither be created nor can it be destroyed. It only changes from one form to another.
संबंधित प्रश्न
When do we say that work is done?
A force of 30 N acts on a body and moves it through a distance of 5 m in the direction of force. Calculate the work done by the force.
The velocity of a car increases from 54 km/hr to 72 km/hr. How much is the work done if the mass of the car is 1500 kg?
What is the work done against gravity when a body is moved horizontally along a frictionless surface?
Write an expression for work done by a force depends?
State the energy changes which take place when A piece of magnesium wire is burnt in a jar of oxygen.
State the energy changes which take place when A stone dropped from the top of a cliff reaches the ground after some time.
A girl of mass 40 kg runs a height of 80 stairs, each 25 cm high with a load of 20 kg on her head in 25 sec. If g is 10 m/s2, find:
(i) Gravitational force acting on the girl.
(ii) Work done by her.
(iii) Useful work done by her.
(iv) Her power in watt.
