Q.1
• a) True
• b) False
Q.2
##### For which of the following does the centre of mass lie outside the body?
• a) Pen
• b) Dice
• c) Rectangular tile
• d) Bangle
Q.3
• a) A
• b) B
• c) C
• d) D
Q.4
##### Numerous particles in a system are placed at a distance of “D” from the origin. The position of the centre of mass will definitely be _____
• a) Equal to D
• b) Lesser than or equal to D
• c) Greater than D
• d) Greater than or equal to D
Q.5
##### An asteroid enters the atmosphere of the earth and breaks into two pieces. One of the pieces is larger than the other. Which of the following is true considering the centre of mass of both the pieces together?
• a) The centre of mass shifts horizontally towards the larger piece
• b) The centre of mass shifts horizontally towards the smaller piece
• c) The centre of mass remains in the same trajectory as before breaking apart of the asteroid
• d) Depends on the velocity of the asteroid
Q.6
##### Consider a system on which there are external forces acting. If the vector sum of all these external forces is zero, then the centre of mass _____
• a) must not move
• b) may move
• c) may accelerate
• d) must accelerate
Q.7
##### For an object with the centre of mass at the origin, the x-coordinates of particles of the object _____
• a) may be all positive
• b) may be all negative
• c) may be all non-negative
• d) cannot be predicted
Q.8
##### Two bodies of masses 5 kg and 3 kg are moving towards each other at velocities of 3 m/s and 5 m/s, respectively. What is the velocity of their centre of mass?
• a) 0.25 m/s towards 3 kg
• b) Upredictable
• c) The centre of mass is stationary
• d) 0.5 m/s towards 5 kg
Q.9
##### The velocities of three particles of masseskg,kg andkg are 10i,andm/s, respectively. What is the velocity of their centre of mass?
• a) (i + 2j + 3k) m/s
• b) 10 (i + j + k) m/s
• c) (10i + 20j + 30k) m/s
• d) (3i + 2j + k) m/s
Q.10
• a) a/4
• b) a/2
• c) a
• d) 2a
Q.11
• a) 0
• b) 0.8v
• c) 80v
• d) 8v
Q.12
• a)0 cm
• b) 1 cm
• c) 2 cm
• d) 3 cm
Q.13
• a) True
• b) False
Q.14
##### In the figure shown below, all the contact surfaces are perfectly smooth. “M” and “m” indicate mass. When the object of mass “m” starts sliding down due to the force of gravity, then the centre of mass will _____
• a) remain unchanged
• b) change horizontally
• c) change vertically
• d) change both horizontally and vertically