How many coins 1.75 cm in diameter and 2 mm thick must be melted to form a cuboid 11 cm × 10 cm × 7 cm?
Answers
Answer:
The number of coins are 1600.
Step-by-step explanation:
Each coin is a cylinder . Given :
Thickness of a coin ,h = 2 mm = 2/10 = 0.2 cm
[1 mm = 1/10 cm]
Dimension of cuboid = 11 cm × 10cm × 7cm
Diameter of a coin = 1.75 cm
Radius of a coin , r = 1.75/2 = 0.875 cm
Volume of a coin (cylinder) = πr²h
= 22/7 ×( 0.875)² × 0.2
Volume of cuboid = L × B × H = 11 cm × 10cm × 7cm
Number of coins = volume of cuboid / volume of coin
= 11cm × 10cm × 7cm / 22/7 ×( 0.875)² × 0.2
= (11 × 10 × 7 × 7) / 22 × 0.875 × 0.875 × 0.2
= 10/ 2 × 0.125 × 0.125 × 0.2
= 10 / .00625
= 1000000/ 625 = 1600
Number of coins = 1600
Hence, the number of coins are 1600.
HOPE THIS ANSWER WILL HELP YOU….
Thickness of a coin ,h = 2 mm = 2/10 = 0.2 cm
[1 mm = 1/10 cm]
Dimension of cuboid = 11 cm × 10cm × 7cm
Diameter of a coin = 1.75 cm
Radius of a coin , r = 1.75/2 = 0.875 cm
Volume of a coin (cylinder) = πr²h
= 22/7 ×( 0.875)² × 0.2
Volume of cuboid = L × B × H = 11 cm × 10cm × 7cm
Number of coins = volume of cuboid / volume of coin
= 11cm × 10cm × 7cm / 22/7 ×( 0.875)² × 0.2
= (11 × 10 × 7 × 7) / 22 × 0.875 × 0.875 × 0.2
= 10/ 2 × 0.125 × 0.125 × 0.2
= 10 / .00625
= 1000000/ 625 = 1600
Number of coins = 1600
Hence, the number of coins are 1600.