A string of linear mass density 0.5 g cm−1 and a total length 30 cm is tied to a fixed wall at one end and to a frictionless ring at the other end. The ring can move on a vertical rod. A wave pulse is produced on the string which moves towards the ring at a speed of 20 cms−1. The pulse is symmetric about its maximum which is located at a distance of 20 cm from the end joined to the ring. Assuming that the wave is reflected from the ends without loss of energy, find the time taken by the string to regain its shape.
A string of linear mass density 0.5 g cm−1 and a total length 30 cm is tied to a fixed wall at one end and to a frictionless ring at the other end. The ring can move on a vertical rod. A wave pulse is produced on the string which moves towards the ring at a speed of 20 cms−1. The pulse is symmetric about its maximum which is located at a distance of 20 cm from the end joined to the ring. Assuming that the wave is reflected from the ends without loss of energy, find the time taken by the string to regain its shape.
The correct option is A 2 sec
μ = 0.5g cm−1 = 0.5 × 10−1 kg/m
l = 30 cm = 0.3 m
v + 20 cm s−1 = 0.2 ms−1
Since it's a free and end and not fixed one so the reflected wave will be in phase and be reflected as it is so the pulse will have to travel 40 cm
v = 20 cm/s
⇒ time = 2sec
2 sec
μ = 0.5g cm−1 = 0.5 × 10−1 kg/m
l = 30 cm = 0.3 m
v + 20 cm s−1 = 0.2 ms−1
Since it's a free and end and not fixed one so the reflected wave will be in phase and be reflected as it is so the pulse will have to travel 40 cm
v = 20 cm/s
⇒ time = 2sec
