A steel pipe is 5 meters long, 20 cm in diameter and 2 cm in wall thickness. If the weight of steel per cubic decimeter is 7.8 kg, how many kg is the weight of this steel pipe Keep integers

A steel pipe is 5 meters long, 20 cm in diameter and 2 cm in wall thickness. If the weight of steel per cubic decimeter is 7.8 kg, how many kg is the weight of this steel pipe Keep integers

Outer radius = 10 cm
Inner radius = 10-2 = 8 cm
Volume = 500 × 3.14 × (10 & # 178; - 8 & # 178;) = 56520 cubic centimeter = 56.52 cubic decimeter
Mass = 56.52 × 7.8 = 440.856kg

A cylindrical steel pipe. The inner diameter is 8 cm. The outer diameter is 12 cm. The length is 4 meters. Each cubic centimeter of steel weighs 7.8 grams. How many kilograms does this steel pipe weigh?

4m = 400cm
The radius is inside
8 △ 2 = 4 (CM)
What is the outer radius
12 △ 2 = 6 (CM)
What is the volume of the steel pipe
(6 × 6 × 3.14-4 × 4 × 3.14) × 400 = 25120 (cm3)
Steel pipe weight
7.8 × 25120 = 195936 (g) = 195.936 (kg)

A cylindrical steel pipe (as shown in the figure) is 4m long and weighs 7.8G per cubic centimeter. How many kg does this steel pipe weigh?

4 M = 400 cm, the inner radius of the steel pipe is 8 △ 2 = 4 (CM); the outer radius of the steel pipe is 12 △ 2 = 6 (CM); the volume of the steel pipe is 3.14 × (62-42) × 400, = 3.14 × (36-16) × 400, = 3.14 × 20 × 400, = 25120 (CC), the weight of the steel pipe is 7.8 × 25120 = 195936 (g) = 195.936 (kg); a: the weight of the steel pipe is 195.936 kg