Q1) Calculate the work done by a person in lifting a load of 20 kg from the ground and placing it on a 1-m-high table.

Q2)A 2-kg body is sliding up an inclined plane of inclination 30°. Find the work done by the force of gravity in moving the body through 1 m.

Q3) A force of 12 N does a work of 12J on a body when the body is displaced through 2 m. At what angle to the displacement does the force act?

Q4) Find the mass of a body which has 5 J of kinetíc energy while moving at a speed of 2 m/s.

Q5) Calculate the speed of a body of mass 200 g having a kinetic energy of 10 J.

Q6) A body of mass 25 g has a momentum of 0.40 kg m/s.Find its kinetic energy.

Q7) The mass of a ball A is double the mass of another ball B. The ball A moves at half the speed of the ball B.Calculate the ratio of the kinetic energy of A to the kinetic energy of B.

Q8) Calculate the increase in potential energy as a block of 2 kg is lifted up through 2 m.

Q9) A ball of mass 0.5 kg is dropped from a height. Find the work done by its weight in one second after the ball is dropped.

Q10) A ball of mass 1 kg is dropped from a height of 5 m. (a) Find the kinetic energy of the ball just before it reaches the ground. (b) What is its speed at this instant?

Q11) A block is thrown upwards with a kinetic energy 1 J. If it goes up to a maximum height of 1 m, find the mass of the block.

Q12) A cycle together with its rider weighs 100 kg. How much work is needed to set it moving at 3 m/s?

Q13) A man performs 120 J of work in 6 s. Calculate the power.

Q14) Two persons do the same amount of work. The first person does it in 10 s and the second, in 20 s. Find the ratio of the power used by the first person to that by the second person.

Q15) How much work is done at the rate of 40 W in 40 s?

Q16) A 100-W electric bulb is used for five hours. How much energy is consumed by the bulb?

Q17) A 1000-W heater is used for 1 hour every day for 30 days. Find the cost of electricity if the rate is Rs 3.00/unit.