Question

A rectangular strip 25 cm × 7 cm is rotated about the longer side. Find the volume of the solid, thus generated.

Answer 1

Given,

Dimensions of rectangular srip = 25 cm × 7 cm

When it rotated about longer side:

Radius of base = 7 cm

Height of cylinder = 25 cm

∴ Volume of cylinder = πr²h = \(\frac{22}{7}\) x 7 x 7 x 25 = 3850 cm³