Question

An insect moves along the sides of a wall of dimensions 12m × 5 m starting from one corner and reaches the diagonally opposite corner. If the insect takes 2 s to reach the diagonally opposite corner, then find the ratio of average speed to the average velocity of the insect.

• A. 17:13
• B. 12:5
• C. 10:5
• D. 13:12

Answer 1

The correct option is A

17:13

Displacement $=\sqrt{{12}^2+5^2}$

=13 m

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

Now,

Total distance =(12+5)

=17 m

Average speed $=\frac{\text{Total distance}}{time}$

$=\frac{17}{2}m/s$

Now,

Ratio of average speed to average velocity

$=\frac{\frac{17}{2}}{\frac{13}{2}}=\frac{17}{13}$