De hemel for work done by a constant force
1. Che wesamples were energy is possessed by a body due to its change in shape
State and prove the law of conservation of energy
5. Is it possible that force is acting on a body but still work done is sero? Explain
6. A rocket of mass30 kg takes off from a launching pad and acquires a vertical
velocity of 1kms at an altitude of 25 km. calculate (a) the potential energy and the
kinetic energy. (g = 9.8m2)
7. If a man lifts a load up with the help of a rope such that it raises the load of mass 50kg
to a height of 20m in 100 sec. Find the power of man
8. A ball is dropped from a height of 5m. Find the velocity of the ball just before it
reaches the ground. Do you require the value of mass to find the velocity?
9. Two persons A and B do same amount of work. The person A does that work in tec
and the person b in sec. Find the ratio of power delivered by them.
10. Why do our hands become warm when rubbed against each other? Explain
11. The kinetic energy of a body of mass 15 kg is 30). What is its momentim?
12. Give an example for each of the following energy conversion: (1) electrical energy to
kinetic energy. (2) Chemical energy to electrical energy (3) sound energy to electrical
energy
13. Two bodies have same momentum. Which will have greater kinetic energy-heavier
body or lighter body?
14. An electric bulb of 60w is used for th per day.Calculate the units of energy
consumed in one day by the bulb.
15. A boy of mass 50kg runs up to a staircase of 45 steps in 9s. If the height of a step is
15cm, find his power. ( - 10m/s)
16. Two particles of masses ig and 2g have equal momentum. Find the ratio between
their kinetic energies?
17. What will be the work done by the string, when a stone is tied to a string and whared
in a cicle?
18. A locomotive exerts a force of 7500N and pulls a train through 15 km. How much
work is done by locomotive?
19. What work a boy of mass 50kg will do in order to increase running speed from
9kmh to 18km
20. The speed of a moving body is halved. What is the change in its KE?
21. State the energy changes taking place in the following cases: (1) A car moves up
hilly road.(2) a stone projected vertically upward returns
22. When we catalog of wood with a saw it becomes warm, why?
Answers
Answer:
De hemel for work done by a constant force
1. Che wesamples were energy is possessed by a body due to its change in shape
State and prove the law of conservation of energy
5. Is it possible that force is acting on a body but still work done is sero.
6. A rocket of mass30 kg takes off from a launching pad and acquires a vertical
velocity of 1kms at an altitude of 25 km. calculate (a) the potential energy and the
kinetic energy. (g = 9.8m2)
7. If a man lifts a load up with the help of a rope such that it raises the load of mass 50kg
to a height of 20m in 100 sec. Find the power of man
8. A ball is dropped from a height of 5m. Find the velocity of the ball just before it
reaches the ground. Do you require the value of mass to find the velocity.
9. Two persons A and B do same amount of work. The person A does that work in tec
and the person b in sec. Find the ratio of power delivered by them.
10. Why do our hands become warm when rubbed against each other.
11. The kinetic energy of a body of mass 15 kg is 30). What is its momentim?
12. Give an example for each of the following energy conversion: (1) electrical energy to
kinetic energy. (2) Chemical energy to electrical energy (3) sound energy to electrical
energy
13. Two bodies have same momentum. Which will have greater kinetic energy-heavier
body or lighter body.
Step-by-step explanation:
make me as brain list
De hemel for work done by a constant force
1. Che wesamples were energy is possessed by a body due to its change in shape
State and prove the law of conservation of energy
5. Is it possible that force is acting on a body but still work done is sero.
6. A rocket of mass30 kg takes off from a launching pad and acquires a vertical
velocity of 1kms at an altitude of 25 km. calculate (a) the potential energy and the
kinetic energy. (g = 9.8m2)
7. If a man lifts a load up with the help of a rope such that it raises the load of mass 50kg
to a height of 20m in 100 sec. Find the power of man
8. A ball is dropped from a height of 5m. Find the velocity of the ball just before it
reaches the ground. Do you require the value of mass to find the velocity.
9. Two persons A and B do same amount of work. The person A does that work in tec
and the person b in sec. Find the ratio of power delivered by them.
10. Why do our hands become warm when rubbed against each other.
11. The kinetic energy of a body of mass 15 kg is 30). What is its momentim?
12. Give an example for each of the following energy conversion: (1) electrical energy to
kinetic energy. (2) Chemical energy to electrical energy (3) sound energy to electrical
energy
13. Two bodies have same momentum. Which will have greater kinetic energy-heavier
body or lighter body.