Question

A person on a motor cycle gains a speed of 10 kmph to 60 kmph in 10 secs. the angular rotation of the needle in the speedometer is about 200 degrees. what will be the angular speed in degrees/sec?

Answer 1

The angular speed of the speedomenter needle while accelerating at that rate is:

w = (200/360)*(2 pi)rad/10 sec

= (5/9)*2*pi/10 = pi/9 radians/s

Answer 2

Rotational motion is the circular motion of an object about an axis of rotation. We will discuss specifically circular motion and spin.

Angle of rotation, which is the angular equivalence of distance and angular velocity, which is the angular equivalence of linear velocity.

                            $\omega = \frac {200} {360} \times (2\pi) rad/10 sec$

                            $\omega = \frac {5} {9} \times 2 \times \pi/10 \\= \frac{\pi}{9} radian/s$