Question

A man standing near a cliff with a seconds pendulum fires a gun when the pendulum is at mean position and hears the echo when it just reaches extreme position if speed of sound is 340ms calculate the distance from Cliff

Answer 1

time period for seconds pendulum is 2sec. So,
time to travel pendulum from mean position to extreme position =.5sec
echo time=d/s*2 So,
distance =0.5*340*2=340metres