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Question 30219
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Laws of Motion and Friction: Contact Force MCQ

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Contact ForceHardQuestion 30219

Question

Two blocks A (2 kg) and B (3 kg) are placed in contact. A force F = 25 N pushes A horizontally. The contact force between A and B on a frictionless surface is:
  1. A
    10 N
  2. B
    15 N
    Correct
  3. C
    25 N
  4. D
    5 N

Correct answer

15 N

Explanation

Acceleration a = 25/5 = 5 m/s². Contact force N_AB pushes only B: N_AB = m_B × a = 3 × 5 = 15 N.

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