Short-answer Questions (Dynamics)

1. Distinguish between statics and dynamics.
2. Distinguish between particle and rigid body.
3. Explain the types of motion with suitable examples.
4. Define reference frame. What reference frame is commonly used for engineering analyses?
5. Define position vector and displacement vector.
6. Distinguish between displacement vector and distance travelled.
7. Define velocity of a particle.
8. Define average velocity and instantaneous velocity.
9. Define average acceleration and instantaneous acceleration.
10. Under what conditions is average velocity equal to instantaneous velocity?
11. If a particle moves with constant speed but changes in direction, can there be acceleration.
12. Distinguish between rectilinear motion and curvilinear motion.
13. State the differential equations of motion.
14. Distinguish between uniform motion and uniformly acceleration motion.
15. Derive the x-t, v-t and a-t relationships for uniformly acceleration motion.
16. What are motion curves? What are they used for?
17. Differentiate between Relative velocity and Resultant velocity.
18. What is simple harmonic motion?
19. What is a harmonic of a sum of simple harmonic motion.
20. Define free fall.
21. What are the assumptions made in free fall?
22. Define curvilinear motion with suitable examples.
23. Express velocity and acceleration vectors in terms of rectangular components.
24. Define radian. How many radians are equivalent to 180⁰.
25. Define projectile motion and state how such a motion can be considered as a combination of two independent motions occurring simultaneously along perpendicular directions.
26. What are the assumptions made in projectile motion.
27. Derive the equation of path of projectile motion.
28. Prove that a particle that moves under the action of constant gravity describes a parabolic path.
29. Define range of projectile and the condition for maximum range.
30. Derive the expressions for (i) time of flight, (ii) range when a particle is projected on an inclined plane.
31. Derive the condition for maximum range when a particle is projected on an inclined plane and determine the maximum range.
32. Express the acceleration of a particle in tangential and normal components.
33. Define curvature, centre of curvature and radius of curvature in a curvilinear path.
34. Express radius of curvature in mathematical form.
35. Does the concepts of tangential and normal components of acceleration of a particle that moves on a curved path apply only to plane motion of the particle? Explain.
36. What is the osculating plane of a path in space?
37. What are Lissajous figures?
38. What is the direction of centripetal acceleration?
39. What are cylindrical coordinates?
40. Derive the expressions for velocity and acceleration vectors in radial and transverse components.
41. Distinguish between kinematics and kinetics.
42. May g be regarded as a constant in studying the motion of a high-altitude rocket? Explain.
43. Discuss on the experiments of Galileo and his conclusions.
44. Define inertia and how can it be measured.
45. State Newton’s first and second-laws of motion.
46. How is Newton’s first law related to his second law?
47. What property of a particle does its mass measure?
48. Derive the mathematical expression for Newton’s second law of motion.
49. Express the scalar forms of equations of motion.
50. State D’Alembert’s principle.
51. Discuss the forces providing the normal acceleration in circular motions considering various examples.
52. Define work done on a body (a) by a constant force and (b) by a varying force.
53. When is the work done upon a body positive and when it is negative?
54. Under what conditions does the work done upon a body become zero?
55. The work done upon a body by a system of forces causing uniform velocity is zero. Discuss.
56. Derive the expression for work done upon stretching a spring without accelerating it.
57. Define power.
58. What is the relationship between Watt power and Horse power?
59. Define energy. What are the various forms of energy?
60. State the work-energy principle.
61. Explain the work done by internal forces in a connected system.
62. Show that the energy of a freely falling body is constant.
63. Define the term coefficient of restitution
64. How will you calculate the linear restoring force of an elastic material?
65. State the equation to determine the escape velocity of a satellite to escape from the gravitational field of earth.
66. Define linear momentum and angular momentum.
67. Is it more hazardous for a river boat to strike floating logs when it is going downstream or when it is going upstream? Explain.
68. What are impulsive forces?.Give examples.
69. State the principle of conservation of momentum. Give some examples where this principle is applied.
70. Differentiate between the work-energy and impulse – momentum methods.
71. What is the practical difficulty involved when a jet of water strikes a moving plate or vane and how is it overcome.
72. Derive the expression for a mass of water striking an obstruction.
73. What are non-impulsive forces? Give examples.
74. What are the different types of rigid body motions?
75. Define general plane motion, fixed-axis rotation and give examples.
76. Define (i) instantaneous centre of rotation (ii) instantaneous power.
77. Explain how to locate instantaneous centre of rotation in general plane motion.
78. Under what conditions can we neglect the rotational motion of a body?
79. Explain how the sum of internal forces in a system of particles reduces to zero.
80. State the work-energy principle and conservation of mechanical energy for a rigid body.