Question

An insect moves along a circular path of radius 10 cm with a constant speed. If it takes 1 minute to move from a point on the path to the diametrically opposite point, then the distance covered, speed, displacement and velocity respectively are

• A. 3.14 cm, 3.14 cm/min, 10 cm, 10 cm/min
• B. 31.4 cm, 31.4 cm/min, 20 cm, 20 cm/min
• C. 0.314 cm, 0.314 cm/min, 1 cm, 1 cm/min
• D. 314 cm, 314 cm/min, 0.1 cm, 0.1 cm/min

Answer 1

The correct option is B 31.4 cm, 31.4 cm/min, 20 cm, 20 cm/min

Given, radius of the circle, r = 10 cm and time taken, t = 1 minute.
The distance covered = $\pi r$ = 3.14 $\times$ 10
=31.4 cm
Speed $=\frac{\text{distance}}{\text{time}}=\frac{31.4}{1}$
$=31.4cm/min$
Displacement = 2r = 2 $\times$ 10 = 20 cm
velocity $=\frac{\text{displacement}}{\text{time}}$
$=\frac{20}{1}=20cm/min$