Motion in a Straight Line – Solutions
1) In which of the following examples of motion, can body be considered approximately a point object?
(a) A railway carriage moving without jerks between two stations.
(b) A monkey sitting on top of a man cycling smoothly on a circular track.
(c) A spinning cricket ball that turns sharply on hitting the ground.
(d) A tumbling beaker that has slipped off the edge of table.
(a) In comparison to the size of the railway carriages, the distance between the two stations are very large, and hence, the carriage can be considered as a point object.
(b) If the cyclist describes a circular track of a very large radius, then the monkey can be considered as a point object, because in that case the distance covered by the cyclist is quite large as compared to the size of the monkey.