Question

A boy makes one round along the boundary of a rectangular field in 20 minutes.The field is 160 m long and 124 m wide.Find-
(1) The perimeter of the field?
(2) The distance moved by the boy?
(3) The speed (in ms-1) at which the boy runs?

Answer 1

Answer :

Given Length of rectangular field = 160 m
And
Width of rectangular field = 124 m
And
1 ) We know perimeter of rectangle = 2 ( Length + Width )
So,
Perimeter of rectangular field = 2 ( 160 + 124 ) = 2 $\times$ 284 = 568 m ( Ans )

2 ) Distance travelled by boy = Perimeter of rectangular field
So,
Distance travelled by boy = 568 m ( Ans )

3 ) We know Speed = $\frac{Dis\tan ce}{Time}$
And
Given : A boy makes one round along the boundary of a rectangular field in 20 minutes
we know 1 minutes = 60 sec , So
20 minutes = 20 $\times$ 60 = 1200 sec
So,
Speed in m / sec = $\frac{568}{1200}=\frac{71}{150}=\mathbf{}\mathbf{0}\mathbf{.}\mathbf{473}\mathbf{}\mathit{m}\mathbf{}\mathbf{/}\mathit{s}\mathit{e}\mathit{c}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{(}\mathbf{}\mathit{A}\mathit{n}\mathit{s}\mathbf{}\mathbf{)}$