Physics – Work Energy and Power

1. Work done is defined as the dot product of which among the following vectors?

  1. Velocity and acceleration
  2. Displacement and acceleration
  3. Force and velocity
  4. Force and displacement
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Answer: Option D. Force and displacement

2. Which of the following statements is incorrect regarding an inelastic collision?

  1. Momentum is conserved
  2. Kinetic energy is not necessarily conserved
  3. It involves objects sticking together after the collision
  4. The total kinetic energy is conserved
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Answer: Option D. The total kinetic energy is conserved

3. What is the dimensional formula of work done?

  1. M^1L^2T^-2
  2. M^0L^0T^-1
  3. M^0L^-1T^-2
  4. M^0L^-4T^-5
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Answer: Option A. M^1L^2T^-2

4. If two vectors are perpendicular to each other, what would their dot product be?

  1. One
  2. Equal to their magnitudes
  3. Zero
  4. Negative
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Answer: Option C. Zero

5. The dot product of two vectors A and B is equal to the product of magnitudes of A and B and __?

  1. The sine of the angle between them
  2. The cosine of the smallest angle between them
  3. Their cross product
  4. The tangent of the angle between them
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Answer: Option B. The cosine of the smallest angle between them