# Calculate the volume of liquid in liters in the cooling part of the heat pump, if the pipe length is 600m

**Calculate the volume of liquid in liters in the cooling part of the heat pump, if the pipe length is 600m, the wall thickness is 2.5mm, and the outer diameter is 40mm.**

1) In order to solve this problem, we need to use the formula for the volume of a cylinder.

2) We have 2 cylindrical tubes, a small one in the middle of a large one, if we subtract the volume of a large cylinder from a small one, we get the volume of liquid in the cooling part of the heat pump.

3) V (large cylinder) = pR ^ 2H, where p = 3.14, R = 0.5 * 40 mm = 20 mm = 2 cm = 0.02 m.

4) V (small cylinder) = pr ^ 2H, where r = R – 2.5 mm = 0.02 m – 0.0025 m = 0.0175 m.

5) V (large cylinder) – V (small cylinder) = R ^ 2-r ^ 2 = 0.02 ^ 2 – 0.0175 ^ 2H = 0.0004 – 0.00030625 = 0.00009 m3 = 0.00009 l.

Answer: 0.00009 l.