Question

(1) Define kinetic energy. Derive an expression for the kineu 89 0 un vuju
(11)The power of a motor pump is 5kW. How much water per minute the pump can raise to height of 20m?
Take g=10 ms?is
6) List two conditions which need to be satisfied for the work to be done on an object ?
7) Define 1 Watt of power. A lamp consumes 1000 J of electrical energy in 10s. Calculate its power.
8) (1) A light and a heavy object have the same momentum. What is the ratio of their kinetic energies? Which
one has a larger kinetic energy ?
(ii) A ball is dropped from a height of 10m. If the energy of the ball reduces by 40% after striking the ground,
how much high can the ball bounce back ?(g = 10ms)
9) (i) State the law of conservation of energy.
(ii) Show that the energy of a freely falling body is conserved.
10) Define energy. Name and define its SI unit.
11) A child of mass 35kg is sitting on a trolley of mass 5 kg. The trolley is given a push by applying a force so
that begins to move with a speed of 4m/s. The trolley comes to rest after covering a distance of 16 m.
Find (i) the work done on the trolley (ii) the work done by the trolley before coming the nest.
12) (a) An object of mass 'm' is moving with a velocity 'v' on a level ground. State the amount of work done by
a person who wants to stop the object. Justify your answer.
(b) A satellite of mass 'm' is moving round
the earth with a speed 'v'. State the work done by the force of gravity on the satellite. Justify your
answer.
3) When is work said to be done against the force of gravity ? State and define SI unit of work.​

Answer 1

Answer:

kinetic energy means motion between the particles of matterkinetic energy means motion between the particles of matterkinetic energy means motion between the particles of matterkinetic energy means motion between the particles of matterkinetic energy means motion between the particles of matterkinetic energy means motion between the particles of matterkinetic energy means motion between the particles of matterkinetic energy means motion between the particles of matter

Explanation: