Concepts Of Physics MCQ Edition [Volume 1]PhysicsNewton's Laws of Motion
In a simple Atwood machine, two unequal masses m₁ and m₂ are connected by a string going over a clamped light smooth pulley. In an arrangement where m₁ = 300 g and m₂ = 600 g , the system is released from rest. Calculate the tension in the string.
Options
- A5.9 N
- B3.9 N
- C2.9 N
- D7.8 N
Correct answer
B. 3.9 N
Step-by-step solution
Given, m₁ = 300 g = 0.3 kg and m₂ = 600 g = 0.6 kg . Let T be the tension in the string and a be the acceleration of the masses. The equations of motion for the two masses are: m₂ g - T = m₂ a T - m₁ g = m₁ a Solving these equations for tension T , we get: T = 2 m₁ m₂ m₁ + m₂ g Substituting the given values and g = 9.8 m/s ^2 : T = 2 0.3 0.6 0.3 + 0.6 9.8 T = 0.36 0.9 9.8 T = 0.4 9.8 = 3.92 N Rounding to one decimal place, the tension is approximately 3.9 N .