Concepts Of Physics MCQ Edition [Volume 1]PhysicsWave Motion and Waves on a String
For the arrangement shown in the figure, the string has a mass of 4.5 g . Calculate the time required for a transverse disturbance generated at the floor to reach the pulley. Take g = 10 m s ⁻² .
Options
- A10 s
- B0.02 s
- C0.03 s
- D0.0225 s
Correct answer
B. 0.02 s
Step-by-step solution
The total length of the string is the sum of the lengths on both sides of the pulley. l = 2.0 m + 0.25 m = 2.25 m The mass of the string is given as m = 4.5 g = 4.5 10⁻³ kg . The linear mass density of the string is: = m l = 4.5 10⁻³ 2.25 = 2 10⁻³ kg/m The tension T in the string is provided by the weight of the suspended block. Since the mass of the string is negligible compared to the block, the tension is uniform throughout the string. T = Mg = 2 10 = 20 N The speed v of the transverse wave in the string is: v =