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A string passes over a smooth pulley and carries a 2 Kg mass at one end and 1 Kg mass at the other. What is the acceleration of the masses?

Correct answer: A. 3.27 m / sec2

  • A. 3.27 m / sec2
  • B. 19.6 m / sec2
  • C. 4.9 m / sec2
  • D. 170 m / sec2

Explanation

To find the acceleration of the system, first identify the forces acting on the masses. For the 2 Kg mass, the force is 2g (where g = 9.8 m/s²), and for the 1 Kg mass, the force is 1g. The net force on the system is the difference in these gravitational forces, which is (2g - 1g) = 1g. Applying Newton's second law (F = ma) to the entire system (total mass = 2 Kg + 1 Kg = 3 Kg), we get:Net force = total mass × acceleration => 1g = 3aTherefore, a = g/3 = 9.8/3 ≈ 3.27 m/s².Option A is correct as it reflects this calculation. Option B represents the acceleration due to gravity and is not applicable here. Option C is incorrect as it does not match the calculated value, and Option D is an unrealistic and incorrect value for this situation.

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