Question

31. A solid cylinder has radius 20 cm and height 40 cm. The cylinder is melted down. All of the
metal is used to make solid cubes of lengths 2 cm as shown in the diagram below.
Calculate the number of cubes that are made. [Take n = 3.14]​

Answer 1

Step-by-step explanation:

radius of cylinder= 20 cm

height of cylinder= 40cm

surface area of cylinder= 2πrh+2πr^2

2×3.14×20×40+2×3.14×20^2

5024+2512

7536 cm^2

length of cube= 2cm

surface area of cube= 6a^2

6×2×2

24cm^2

Number of cubes= 7356cm^2÷24cm^2

314 number of cubes