The length breadth and thickness of a rectangular object are 4.576 m, 1.243 , and 1.22 cm respectively. Find the area of its face and its volume to correct significant figures.

Options

A. `5.688 m^3, 6.94 xx 10^(-3) m^3`
B. `5.062 m^2, 6.94xx10^(-2) m^3`
C. `5.688 m^2, 10^(-2) m^3`
D. `5.6 m^2, 6.9xx10^(-1)m^3`

Answer

(c )

Explanation

`Here, I = 4.576m, b =1.243 m,`
t =1.22 cm = 0.0122 m
As Area ` =lxxb= 4.576xx1.243 = 5.687968 m^3`
As I and b have 4 significant figures, area shold also be expressed in 4 significant figures.
`:. A = 5.688 m^2` [rounding off to 4 significant figures]
As volume = l xx bxxt
`V = 4.576xx1.243xx 0.0122 = 0.0693932-096 m^3`
As thickness has 3 significant figures, So rounding off volume to 3 significant figures
`V = 6.94 xx 10^(-2) m^3`