Important Questions CBSE Class 9th : Physics Year 2009 (Unsolved)
Chapter 1
(Motion)

Q. 1. What is meant by a body at rest?

Q. 2. Describe a rocket propelled in 30 degrees north of east with a velocity of 5m/s?

Q. 3. What do you mean by a negative displacement?

Q. 4. Justify the statement “Displacement of a particle is independent of the path taken”?

Q. 5. Define the term velocity?

Q. 6. Define the term negative acceleration?

Q. 7. Why is the motion of satellites around the earth is is considered an accelerated motion?

Q. 8. What do you mean by angular velocity?

Chapter 2
(Forces and Laws of motion)

Q. 9. What do you mean by a force?

Q. 10. Give an example of a balanced force?

Q. 11. Can force change the shape of an object? Give an example to prove your point?

Q. 12. Do action and reaction force react in the same direction?

Q. 13. Why a moving ship does takes longer time as compared to a car when equal breaks are applied?

Q. 14. Why are passengers through in forward direction when a running bus stops suddenly?

Q. 15. Why do passengers tend to fall sideways when the bus takes a sharp u turn?

Q. 16. Why should a passenger hold on to prevent himself from swaying in a turning bus?

Q. 17. Why do passengers tend to fall back when it starts suddenly?

Q. 18. Why do passengers jumping out of a rapidly moving bus fall forward with his face downwards, if he does not run forward?

Q. 19. Why does a passenger jumping out of a rapidly moving bus fall forward with his face downwards?

Q. 20. Why can dust be removed by shaking it, or beating it by a carpet?

Q. 21. Why does a bullet when fired against a glass window pane make a hole in it, and the glass pane will smash it?

Q. 22. Why does an athlete take a longer jump if he comes running from a distance than when he jumps suddenly from the take-off line?

Q. 23. What happens when you shake a wet piece of cloth? Explain, why?

Q. 24. Why is it advised to tie a rope on the luggage while you travel by the bus?

Q. 25. How does a boat move forward into the water when the boatman presses one end of the pole against the ground?

Q. 26. Why is it difficult for a fireman to hose, which ejects large amount of water at a high velocity?

Chapter 3
(Gravitation)

Q. 27. What The earth attracted to each other by gravitational force. Does the earth attract the moon, with a force that is greater, or smaller, or the force with which the moon attracts the earth? Why?

Q. 28. The earth attracts the moon. Does the moon attract the earth? If it does, why does the earth not move towards the moon?

Q. 29. How are ocean tides caused?

Q. 30. What do we call the gravitational force between the earth and your body?

Q. 31. The earth attracts an apple. Does the apple also attract the earth? If it does, why does the earth not move towards the apple?

Q. 32. Is the gravitational acceleration independent of mass? Name the experiment which concluded this?

Q. 33. Where do we observe the maximum value of the gravitational acceleration? Equator, poles or Mt Everest?

Q. 34. You must have seen two types of balances, one is the spring balance and the other is the one with the kabadiwalas. Which one of it would you use to measure the mass of an object? Why?

Q. 35. Why does a buffalo float on the river but not the man?

Q. 36. Why does ice float on the water?

Q. 37. Why does a ship made up of iron floats but the iron sinks?

Q. 38. How do submarines float or sink as desired?

Q. 39. Why does a mug full of water appear lighter inside the water?

Q. 40. A dead body floats in water with its head immersed in water. Explain?

Q. 41. In what direction does the buoyant force on an object, due to liquid act?

Q. 42. Why does a block of plastic piece left under water cone to the surface of water?

Q. 43. Write the condition under which the body would float on a liquid?