Q. Two pulses travel in mutually opposite directions in a string with a speed of $2.5\ cm/s$ as shown in the figure. Initially the pulses are $10cm$ apart. What will be the state of the string after two seconds
A) [image:15_image14.png]
B) [image:15_image15.png]
C) [image:15_image16.png]
D) [image:15_image17.png]
Explanation
(c) After two seconds each wave travel a distance of $2.5 \times 2 = 5\ cm\ i.e.$ the two pulses will meet in mutually opposite phase and hence the amplitude of resultant will be zero.
[image:15_image57.png]
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.