Give an example when we infer the motion indirectly.
We infer the motion of air by observing the movement of dust particles or leaves and branches of trees, or simply by feeling the blowing air on our face.
What is the relation between linear velocity and angular velocity?
Linear velocity = Angular velocity × Radius of circular path.
Define one radian.
It is the angle which is subtended at the centre by an arc having a length equal to the radius of the circle.
What do you mean by 2 m/s2?
The velocity of the body increases by 2 m/s after every second.
Suppose a ball is thrown vertically upwards from a position P above the ground. It rises to the highest point Q and returns to the same point P. What is the net displacement and distance travelled by the ball?
Displacement is zero. Distance is twice the distance between position P and Q.
Are rest and motion absolute or relative terms?
They are relative terms.
The phenomenon of motion was placed on a sound scientific footing by two scientists. Write their names.
Galileo Galilei and Isaac Newton.