Question-1
(a) Define work and write its S.I unit. [2 Mark]
(b) Define energy and establish relationship between S.I unit & commercial unit of energy. [2 Mark]
(c)Two bodies A and B of masses 1 kg and 4 kg respectively have equal momentum find ratio of their K.E. [2 Mark]
Question-2
(a) The work done by the heart for each beat is 1 joule. calculate the power of heart if it beats 72 times in a minute. [3 Mark]
(b)The engine of train has yo apply a force of 5000 N to overcome friction to run at a uniform rate of 90 km/hr. What is the power developed by the engine? [3 Mark]
(c)Differentiate between renewable and non-renewable form of energy resource. [2 mark]
Section-B
Question-1 State the conditions in
which force applied on a body does no work. [2
Mark](a) Derive formula of K.E. [4 Mark]
(b) A 40 newton object is released from a height of 10 m. Just before it hits the ground. By which amount its kinetics energy decreased in joules. [2 Mark]
(c) The kinetic energy of a body is 250J. Find work done to move a body of mass 20kg up-to a height of 5 m. [4 Mark]
(d) A 78-kg skydiver has a speed of 62 m/s at an altitude of 870 m above the ground.
i. Determine the kinetic energy possessed by the skydiver.
ii. Determine the potential energy possessed by the skydiver.
iii. Determine the total mechanical energy possessed by the skydiver. [4 Mark]
Question-2
(a) Calculate the work done in lifting 100 kg of water through a vertical height of 5 m. [2 Mark]
(c) What kind of energy transformation takes place when a body is dropped from a certain height? [4 Mark]
Question-3
(a) A jumper has a mass of 52 kg. She is moving with a speed of 2 m/s at a height of 54.6 meters above the ground. Determine the total mechanical energy of the jumper and work done to throw a shot put of weight 2.5 kg upto the height 20 m. [4 Mark]
(b) Calculate the work done in lifting 200 kg of water through a vertical height of 6 m? [4 Mark]
