Question

(a) What do you mean by rest and motion?
(b) Distinguish between distance and displacement.
(c) Define speed and velocity.
(d) Define acceleration.

Answer 1

(a) If an object does not change its position with respect to its surroundings with the passage of time, then it is said to be at rest.
If an object changes its position with respect to its surroundings with the passage of time, then it is said to be in motion.

(b) The total length of actual path travelled by an object is called as distance, While the straight line distance between the initial and final position of an object is called as displacement.

Distance is a scalar quantity while displacement is a vector quantity.

(c) Speed of an object is the time rate at which a certain distance is covered. Velocity of an object is the time rate at which a certain displacement is made.

(d) Rate of change of velocity is called as acceleration.