Question

A rectangular piece of metal 12 cm long 18 cm wide and 10 cm high is melted and recast into 45 cylindrical plates,each of radius 1.2 cm.Find the thickness of each plate giving your answer correct to 2 decimal places?

Answer 1

Answer:

10.61 cm

Step-by-step explanation:

From the question,

The volume of the rectangular piece of metal = Volume of the 45 cylindrical plates.

Volume of a cuboid = 45×volume of a cylinder

lwh = 45×πr²h..................... Equation 1

Where l = length of the rectangular piece of metal, w = width of the rectangular piece of metal, h = height of the rectangular piece of metal, r = radius of the cylindrical plates, h = thickness of the cylindrical plates.

make h the subject of the equation

h = lwh/(45πr²).................... Equation 2

Given: l = 12 cm, w = 18 cm, h = 10 cm. r = 1.2 cm

Constant: π = 3.142.

Substitute these values into equation 2

h = (12×18×10)/(45×3.142×1.2²)

h = 2160/203.60

h = 10.61 cm.