Question

If diameter of a road roller is 0.9 m and its length is 1.4 m, how much area of a field will be pressed in its 500 rotations ?

Answer 1

Length of the road roller, $h=1.4m$
Radius of the road roller, $r=\frac{0.9}{2}=0.45m$
Now, Area of the field pressed in one rotation $=$ Curved surface area of the road roller
$=2\pi rh$
$=2\times \frac{22}{7}\times 0.45\times 1.4$
$=3.96m^2$
$\therefore$ Area of the field pressed in $500$ rotations $=500\times$Area of the field pressed in one rotation $=500\times 3.96=1980m^2$
Thus, the area of the field pressed in $500$ rotations is $1980m^2$