Question

The diameter of a roller is 84cm and it's length is 120cm.it takes 500 complete revolutions to roll once over the play ground to level. Find the area of the play ground in meters square

Answer 1

Diameter = 84 cm

Radius = 84/2 = 42 cm

Length = 120 cm

Curved Surface Area = 2πrh = 2*(22/7)*42*120 = 2*22*6*120 = 31680 cm^2

Revolution = 500

Area covered = 500*31680 = 15840000 cm^2

Hope it helps you...

Please mark it as brainliest...

Answer 2

==> D = 84cm

==> R = 84/2 = 42cm

==> L = h = 120cm.

===> C.S.A = 2πrh

===> = 2 × 22/7 × 42 × 120

===> = 2 × 22 × 6 × 120

===> = 31680cm^2

complete revolution = 500

=========> 500 × 31680

Area of playground in cm^2 = 15,840,000cm^2

Find in m^2

1m^2 = 10,000cm^2

( 1m = 100 cm

1m^2 = 100cm × 100cm = 10,000cm^2)

1m^2 = 10,000cm^2

15840000 = 15840000/10000 = 1584m^2