Question

Metallic discs of radius 0.75 cm and thickness 0.2 cm are melted to obtain 508.68 cm³ of metal. Find the number of discs melted (use π = 3.14).

Answer 1

Radius of metallic disc = 0.75 cm

Thickness of disc = 0.2 cm

Total volume of material which will be used in forming/melting of disc = 508.68 cm³

∴ Material required for one disc = Volume of cylinder

= πr²h

= `22/7 xx 0.75 xx 0.75 xx 0.2`  ...[∵ Shape of a disc is a cylinder]

= 3.14 × 0.75 × 0.75 × 0.2

= 0.35325 cm³

Number of disc can be melted

= `"Total volume of metal obtained after melting"/"Volume of one disc"`

= `508.68/0.35325`

= 1440 discs