Question

Q1.A roller of dia. 14 cm and length 7 cm is rolled along a flat ground. Calculate the area covered when the roller makes 25 revolutions.

Answer 1

Explanation:

Given

Given

Diameter of roller = 14 cm

Length of roller = 7 cm

Revolution made = 25

$\huge \pmb{ \bf{To \: Find}}</p><p>$

Area covered

${ \huge{ \pmb{ \bf{Solution}}}}$

At first we need to find Radius of roller

Radius = Diameter/2

Radius = 14/2

Radius = 7 cm

We know that

$</p><p>{ \large { \pmb{ \bf{CSA = 2\pi rh}}}}$

CSA = 2 × 22/7 × 7 × 7

CSA = 44/7 × 49

CSA = 44 × 7

CSA = 308 cm²

Finding area covered

$</p><p>{ \large{ \bf{ \pmb{ Area \: covered = Revolution \times CSA}}}}$

Area covered = 25 × 308

Area covered = 7700 cm².