Solution:

Length of the roller, h = 2 m = 200 cm [1m = 100 cm]

Inner diameter = 35 cm

Inner radius, r = 35/2 cm

Thickness = 7 cm

Outer radius, R = (35/2)+7

= (35+14)/2

= 49/2 cm

Volume of the iron in roller = (R²-r²)h

= (22/7)[( 49/2)²-(35/2)²]200

= (22/7)[( 49²-35²/4]200

= (22/7)×50( 49²-35²)

= (22/7)×50( 49²-35²)

= (22/7)×50 (2401-1225)

= (22/7)×50×1176

= 184800 cm³

Given 1 cm³ of iron weighs 8 g.

Weight of the roller = 184800×8 = 1478400 g

= 1478.4 kg [1 kg = 1000 g]

Hence the weight of the roller is 1478.4 kg.