when a fire hose is hook up to a water supple and the water is turn on the it frequently takes a firefighter to control the hose. why does a fire hose "recoil" when the water is turned on?
The total momentum of the fireman/hose water remains zero as it was before the water was shot out. Therefore as the water goes right, the hose/fireman goes left.
When a fire hose is hooked up to a water supply and the water is turned on, it often takes a firefighter to control the hose due to its recoil. The recoil effect occurs because of Newton's third law of motion, which states that for every action, there is an equal and opposite reaction.
To understand this, let's break it down step by step:
1. Water pressure: When the water supply is turned on, water rushes into the fire hose under pressure. The pressure inside the hose builds up rapidly.
2. Reaction force: As water enters the hose at high pressure, it exerts an equal and opposite force in the opposite direction according to Newton's third law. This is the reaction force.
3. Equal and opposite forces: The reaction force pushes against the water in the hose, trying to push it back out of the hose in the opposite direction. At the same time, this reaction force pushes against the hose itself.
4. Recoil effect: This force causes the hose to try to straighten out and push back against the firefighter. The water pressure inside the hose wants to release and push itself backward, which generates the recoil effect.
5. Firefighter control: To control the hose, the firefighter needs to apply an opposing force to counteract the recoil. They do this by gripping the hose tightly and using their body weight and strength to anchor it and prevent it from moving.
In summary, the recoil effect in a fire hose occurs due to the water pressure inside the hose exerting an equal and opposite reaction force. This force pushes the hose and tries to straighten it, resulting in the hose "recoiling." Firefighters need to apply an opposing force to control the hose and direct the water flow.