Question

Classify the following as motion along a straight line, circular or oscillatory motion.
(i) The motion of hands while running
(ii) The motion of a horse pulling a cart on a straight road.
(iii) The motion of a child in the merry-go-round.
(iv) The motion of a child on a see-saw.
(v) The motion of a hammer on an electric bell.
(vi) The motion of a train on a straight bridge.

Answer 1

When a body changes its position with respect to the time it is said to be in motion or moving. Motion is written using the terms displacement, distance, speed, time, acceleration, and velocity. An object is said to be in motion if its position is changed with respect to the observer. There are the main six types of motion.

Complete step by step solution:
Step I:
Straight Line Motion: An object which changes its position with time only in a straight line is called a straight-line motion.
Circular Motion: It is the motion in which the object rotates along a circular path. Circular motion can be uniform or nonuniform.
Oscillatory Motion: It is the type of motion in which the object repeats the same type of movement again and again. The object moves to and fro about its mean position.
Step II:
(i) The motion of the hands is to and fro motion as it can be repeated over and over again. So, it is a type of oscillatory motion.
(ii) It is told that the horse cart is moving in a straight line. So it is a type of straight-line motion.
(iii) In a merry-go-round, the motion follows a circular path. Therefore, it is a type of circulatory motion.
(iv) In a see-saw, the movement of the see-saw is repeated again and again in the same pattern. So, it is a type of oscillatory motion.
(v) When a hammer strikes on an electric bell, it moves to and fro about its mean position and repeats the same pattern. It is a type of oscillatory motion.
(vi) It is given that the train is moving on a straight bridge. So it is a type of straight-line motion

Note:
The straight-line motion is also called linear motion. The linear motion is sometimes also called rectilinear motion. But in the case of rectilinear motion, two particles of the body travel along two parallel straight lines and travel the same distance.