Question

Please help with this too​

Answer 1

Answer:

Step-by-step explanation:

Garden roller is in the shape of cylinder.

So, one revolution =  Curved surface area of the cylinder

diameter  = 70 cm

radius = 70/2 = 35 cm

h = 100 cm

Curved surface area of the cylinder = 2πrh

                                                           = $2*\frac{22}{7}*35*100$

                                                           = 22000 square cm

Area covered in 15 revolutions = 15 * 22000

                                                    = 330000 square cm

2) Coin

diameter = 22 mm

r = 22/2 = 11 mm

Volume of coin = 66 mm

πr²h = 66

$\frac{22}{7}*11*11*h=66\\\\\\h=\frac{66*7}{11*11*22}\\h=0.17 mm$