Wave Mechanics Question 656

Question: Two pulses in a stretched string whose centres are initially 8 cm apart are moving towards each other as shown in the figure. The speed of each pulse is 2 cm/s. After 2 s, the total energy of the pulses will be

Options:

A) Zero

B) Purely kinetic

C) Purely potential

D) Partly kinetic and partly potential

Show Answer

Answer:

Correct Answer: B

Solution:

[b] After 2 s, the each wave travels a distance $ =2,\times 2=4m. $ The wave shape is shown in figure. Thus energy is purely kinetic.