Question

Please help with this too​

Answer 1

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*(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

`(22)/(7)*11*11*h=66\\\\\\h=(66*7)/(11*11*22)\\h=0.17 mm`