Very short answer type questions (1 mark each)
1. Is work a vector quantity?
2. What is the SI unit of work?
3. Name the physical quantities on which the amount of work done depends.
4. Give two examples of the objects having potential as well as kinetic energy.
5. An object is thrown vertically upwards. What is the kinetic energy of the body at the highest point of its motion?
7. A body of mass m falls freely from a height h. What will be its kinetic energy just before it touches the ground?
8. What is the Si unit of power? Define it.
9. A dry cell converts one form of energy into another. Name the two forms.
10. Nare the energy transformations taking place in the following cases.
(a) an arrow released from a bow (b) an electric fan (c) an electric heater (d) a stone falling from a building.
Short answer type questions (2 marks each)
11. Nare the physical quantity whose SI unit is joule. Define the unit joule.
12. Is it possible that a force is acting on a body but still the work done is zero? Explain giving one example.
13. Derive the relationship, W=FS cos theeta
14. State whether or not any work is done in the following cases:
(a) When we twist a wire.
(b) When a person carries a hand bag and walks on a level road.
(c) When a person holds a book in his hand and keeps it stationary.
(d) In the case of a uniform circular motion.
15. What do you understand by these statements?
(a) Work done by a force
(b) Work done against a force
16. If the velocity of a body is increased 3 times, what happens to its kinetic energy?
17. State the law of conservation of energy.
18. The earth moves around the sun in a nearly circular path. How much work is done by the gravity of the sun?
Short answer type questions (3 marks each)
19. What do you conclude from the following relationship?
Kinetic energy (K.E.) = 1/2mv²
20. Derive an expression for the potential energy of a body of mass m, when placed at a height h from the earth's surface.
21. A light and a heavy body have equal kinetic energies, Which has larger momentum?
1. Is work a vector quantity?
2. What is the SI unit of work?
3. Name the physical quantities on which the amount of work done depends.
4. Give two examples of the objects having potential as well as kinetic energy.
5. An object is thrown vertically upwards. What is the kinetic energy of the body at the highest point of its motion?
7. A body of mass m falls freely from a height h. What will be its kinetic energy just before it touches the ground?
8. What is the Si unit of power? Define it.
9. A dry cell converts one form of energy into another. Name the two forms.
10. Nare the energy transformations taking place in the following cases.
(a) an arrow released from a bow (b) an electric fan (c) an electric heater (d) a stone falling from a building.
Short answer type questions (2 marks each)
11. Nare the physical quantity whose SI unit is joule. Define the unit joule.
12. Is it possible that a force is acting on a body but still the work done is zero? Explain giving one example.
13. Derive the relationship, W=FS cos theeta
14. State whether or not any work is done in the following cases:
(a) When we twist a wire.
(b) When a person carries a hand bag and walks on a level road.
(c) When a person holds a book in his hand and keeps it stationary.
(d) In the case of a uniform circular motion.
15. What do you understand by these statements?
(a) Work done by a force
(b) Work done against a force
16. If the velocity of a body is increased 3 times, what happens to its kinetic energy?
17. State the law of conservation of energy.
18. The earth moves around the sun in a nearly circular path. How much work is done by the gravity of the sun?
Short answer type questions (3 marks each)
19. What do you conclude from the following relationship?
Kinetic energy (K.E.) = 1/2mv²
20. Derive an expression for the potential energy of a body of mass m, when placed at a height h from the earth's surface.
21. A light and a heavy body have equal kinetic energies, Which has larger momentum?
