Laws of Motion

1. What is the definition of force?2. What are contact forces?3. What are forces at a distance?4. What is gravity?5. What is a force field?6. What are effects of force?7. Give examples for the force applied to set a stationary body into motion.8. Give examples for the force applied to stop moving bodies.9. Give examples for the force applied to change the speed or direction of a moving body.10. Give examples for the force applied to bring about change in dimensions.11. What is newton’s first law of motion?12. Sub-divide newton’s first law.13. Explain each of the sub-divided laws.14. What is inertia?15. What is law of inertia?16. Explain inertia of rest.17. Explain inertia of motion.18. Give examples for inertia of rest.19. Give examples for inertia of motion.20. What is linear momentum?21. What is the SI unit of linear momentum?22. What is the CGS unit of linear momentum?23. 1 Ns = __________24. 1 dyne second = _________25. What is the formula for finding linear momentum? 26. A body has a linear momentum of 5 Ns. If the velocity of the body is 200 ms-1, find the mass of

the body.27. Calculate the velocity of a body of mass 0.5 kg, when it has a linear momentum of 5 Ns.28. An electron of mass 9*10-31 kg is moving with a linear velocity of 6*107 ms-1. Calculate the

linear momentum of electron.29. A body of mas 200 g is moving with a velocity of 5 ms-1. If the velocity of the body changes to

17ms-1, calculate the change in linear momentum of the body.30. A motorcycle of mass 100 kg is running at 10 ms-1. If its engine develops an extra linear

momentum of 2000 Ns, calculate the new velocity of motorcycle.31. What is newton’s second law of motion?32. What is the formula for finding force?33. Explain how to prove “F = ma”.34. What is absolute unit of force?35. What is absolute unit of force in CGS system?36. What is absolute unit of force in SI system?

37. Define 1 newton.38. Define 1 dyne.39. Explain the relation between newton and dyne.40. What is gravitational unit of force?41. What gravitational unit of force in CGS system?42. What is gravitational unit of force in SI system?43. Define gram-force.44. Define kilogram-force.45. 1 gf = ____ dynes.46. 1 kgf = _____ newton.47. A hockey ball at rest is hit by a hockey stick, such that the force acts on the ball for 0.08s. If the

ball of mass 100g and covers a distance of 80m in 1.6s, find the magnitude of force.48. A car initially at rest picks up a velocity of 72 kmh-1 in 20s. If the mass of the car is 1000 kg find

the force covered by the engine and the distance covered by the car.49. A golfer hits a ball at rest such that the contact between the ball and golf stick is for 0.1s. If the

golf ball covers a linear distance of 400m in 2s, find the magnitude of force applied. Mass of golf ball is 50g.

50. A car of mass 800 kg, moving at 54kmh-1 is brought to rest over a distance of 15m. Find the retarding force developed by the brakes of the car.

51. A cricket player holds a cricket ball of mass 100g by moving his hands backward by 0.75m. If the initial velocity of the ball is 108 kmh-1, find the retarding force applied by the player.

52. A motor cyclist along with the machine weighs 160kg. While driving 72 kmh-1, he stops his machine over a distance of 8m. Find the retarding force of the brakes.

53. A force of 500 dynes acts on a mass of 0.05kg over a distance of 20m. Assuming that the mass initially at rest, find the final velocity and any time for which the force acts.

54. A force of 600 dynes acts on a glass ball of mass 200g for 12s. If initially the ball is at rest, find the final velocity and the distance covered.

55. A bullet of mass 30g and moving with a velocity x hits a wooden target with a force of 187.5N. If the bullet penetrates 80cm, find the value of x.

56. A car of mass 1000 kg develops a force of 500N over a distance of 49m. If initially the car is at rest, find the final velocity and the time for which it accelerates.

57. What is newton’s third law of motion? 58. Explain the law.59. Give examples on the law.60. What is newton’s universal law of gravitation?61. What is the value of the universal gravitational constant?62. What is force of gravity?63. What is mass?64. What is weight?65. What is the SI unit of mass?66. What is the CGS unit of mass?67. What is SI unit of weight?

68. What is the CGS unit of weight?69. What are characteristics of mass?70. Differentiate between mass and weight.71. What are characteristics of weight?72. Explain the variation of acceleration due to gravity due to shape of earth.73. Explain the variation of acceleration due to gravity due to its distance from centre of earth.74. Why do we jerk wet clothes before spreading them on a line?75. Why does dust fly off, when carpet is hit with a stick?76. Why do fruits fall off the branches in the strong wind?77. Why does a pillion rider fall forward, when the driver suddenly applies the brakes?78. Why does a boatman push the bank backward with a long bamboo pole, on launching his boat in

water?79. Why is it difficult to walk on marshy ground?80. Why is it dangerous to jump out of a moving vehicles? How can the danger be minimized?81. Why does a boat-man push water backward with the oars, while rowing a boat?