Question

A boy is running to and fro from point A to point B with a constant speed of 20 m/s. If point A and B are 5 m apart, find the frequency of the to and fro motion undertaken by the boy.

• A. A
• B. A²
• C. 1/A
• D. 1/A²

Answer 1

The correct option is C

1/A

$\text{Given, speed of the boy = 20 m/s.}$
$\text{Distance between A and B = 5 m.}$

$\text{Time taken by the boy to complete one}$
$\text{to and fro motion =}\frac{5m+5m}{20m/s.}$

$\text{Thus, time period of to and fro}$
$\text{motion of the boy = 0.5 seconds.}$

$\text{We know that, frequency =}\frac{1}{Timeperiod}\text{= 2 Hz.}$