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Q4.15: NCERT Physics - Part 1 LAWS OF MOTION 4.15 Solution: Two bodies of masses 10 kg and 20 kg respectively kept on a…
⚠️ Common Exam Traps & Conceptual Pitfalls
Students frequently assume the string tension is the same no matter which block the external 600 N force acts on, treating $T$ as $F- (m_1+m_2)a$; in reality $T$ equals the net force on the block *not* directly pulled, i.e. $T = m_{ ext{other}}\,a$, so you must subtract $ma$ of the block to which the force is applied, not the total mass.
Two bodies of masses 10 kg and 20 kg respectively kept on a smooth, horizontal surface are tied to the ends of a light string. A horizontal force F = 600 N is applied to (i) A, (ii) B along the direction of string. What is the tension in the string in each case?
Step-by-Step Verified Solution
**Answer:** (i) T = 400 N (ii) T = 200 N
**Step-by-Step Explanation:**
Total mass = 30 kg. Acceleration:
(i) Force on A (10 kg): T = 600 - 10 _ 20 = 400 N.
(ii) Force on B (20 kg): T = 600 - 20 _ 20 = 200 N [citation:10].
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