Free Test Center of mass – NEET

Q1: What is the position of the center of mass of two equal masses placed at a distance d apart?

A. At one end B. At the midpoint C. At 3/4th the distance D. At the center of gravity

Q2: If a body is symmetrical and of uniform density, where is its center of mass located?

A. At its geometric center B. Near its edge C. At the origin D. Cannot be determined

Q3: The center of mass of an object follows which law of motion?

A. Newton’s first law B. Newton’s second law C. Newton’s third law D. All of the above

Q4: For a system of particles, the center of mass is defined as:

A. Average of positions B. Average of masses C. Mass-weighted average of positions D. Mass-weighted average of velocities

Q5: The motion of the center of mass of a system is affected by:

A. Internal forces B. External forces C. Friction only D. Gravity only

Q6: A uniform rod is placed on a smooth surface. Its center of mass lies at:

A. One-third its length B. Its midpoint C. One-fourth its length D. Near one end

Q7: Two particles of masses 2 kg and 3 kg are located at (0,0) and (4,0) respectively. The x-coordinate of their center of mass is:

A. 1.6 B. 2.4 C. 3.0 D. 0.5

Q8: Which of the following quantities is conserved for the center of mass in the absence of external force?

A. Acceleration B. Velocity C. Momentum D. Kinetic energy

Q9: In projectile motion of a body that explodes mid-air, the center of mass of fragments follows:

A. A random path B. A curved path C. A straight line path D. The original trajectory

Q10: Which frame of reference is best suited for calculating the center of mass?

A. Non-inertial frame B. Rotating frame C. Inertial frame D. Any frame

Q11: A disk and a ring of same mass and radius are placed on a table. Their centers of mass are:

A. Same for both B. Different C. At different heights D. Ring has no center of mass

Q12: The velocity of center of mass of a two-body system is constant if:

A. Internal forces are acting B. There is no net external force C. Friction is present D. Air resistance is there

Q13: Which coordinate is used to calculate the center of mass in 3D?

A. x only B. x and y C. x, y, z D. Depends on mass

Q14: The center of mass lies outside the body in which case?

A. Sphere B. Cube C. Ring D. Disk

Q15: Does the location of center of mass change with velocity?

A. Yes B. No C. Depends on direction D. Depends on acceleration

Q16: If total external force on a system is zero, what happens to center of mass?

A. Accelerates B. Decelerates C. Moves with constant velocity D. Stops

Q17: What is the center of mass of a uniform semicircular ring of radius R?

A. 0 B. 2R/π C. R/2 D. R

Q18: COM of two masses 4 kg and 6 kg placed at 0 m and 10 m respectively is:

A. 4 B. 5 C. 6 D. 7

Q19: Does center of mass always lie within the body?

A. Yes B. No C. Depends on shape D. Depends on mass

Q20: When a man jumps from a boat, the boat moves in opposite direction. Why?

A. Law of friction B. Newton’s second law C. Law of conservation of momentum D. Law of COM

Quiz for Center of mass