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.