# When spraying water, why does the end of the garden hose have a force opposite to the direction of the water flow?

Physics Asked on January 5, 2021

When spraying water, why does the end of the garden hose have a force opposite to the direction of the water flow? I’m talking about the kind of hose without a nozzle. The hose is of equal diameter from beginning to end. The water should not accelerate in it, so there should be no opposing force at the end of the hose.

If your hose was absolutely perfectly straight, this would be true. However, hoses typically have bends in them. If we look at any given bend (such as the last one in a hose), we find that there is a transfer of momentum from the water to the hose to make up for the fact that the water entering that part of the hose is in a different direction from how it exits. This causes that section of tubing to move, bending another section, causing it to impart momentum to the tube.

We also never see a perfectly straight hose because it is unstable. If you had one, there would be force applied on the entire tube from the outflow of water, ending at the faucet. This causes the tube to bend in one direction or another, and from then on the, previously described effects occur.

Answered by Cort Ammon on January 5, 2021