Subject :NSO Class : Class 8
A sonic 'tape measure' is used to measure the length of a room. It measures a time interval of 0.060 s between transmitting a sound pulse and receiving the echo. The speed of sound in air is 330 m/s.
How far is the reflecting wall from the 'tape measure'?
A5.5 m
B9.9 m
C11 m
D20 m
B
Ans 1:
Class : Class 8
B
Ans 2:
Class : Class 9