'The value of g remains same at all places on the earth surface'. Is this statement true? Give reason for your answer.

If a stone and a pencil are dropped simultaneously in vacuum from the top of a tower, which of the two will reach the ground first ? Give reason.

Express 15 m s^-1 in km h^-1 .

Express each of the following in m s ^-1 —

(a) 1 km h^-1

(b) 18 km min^-1