Question

An insect moves along the sides of a wall of dimensions $12m\times 5m$ starting from one corner and reaches the diagonally opposite corner in 2 s. Find the ratio of the average speed to the average velocity of the insect.

• A. 17 : 13
• B. 12 : 5
• C. 13 : 5
• D. 17 : 12

Answer 1

The correct option is A 17 : 13

The total displacement is $dis=\sqrt{diagonal}=\sqrt{{12}^2+5^2}=13m$

average velocity $v=\frac{13}{2}m/s$

The total distance is $d=12+5=17m$

average speed $u=\frac{17}{2}m/s$

ratio of the average speed to the average velocity of the insect.

$\frac{v}{u}=\frac{17/2}{13/2}=\frac{17}{13}$