Homework Help: physics - fluids

Posted by Nik on Friday, May 2, 2008 at 4:05am.

A fire hose exerts a force on the person holding it. This is because the water accelerates as it goes from the hose through the nozzle. How much force is required to hold a 7.5 cm diameter hose delivering 450 L/min through a 0.80cm diameter nozzle?

physics - fluids - bobpursley, Friday, May 2, 2008 at 6:28am
The velocity will be increased as the inverse ratio of areas:

New velocity/oldvelocity=(7.5/.8)^2

The old velocity can be solved by

450L/min*1dm^3/L * 1min/60sec is flow in dm^3/sec, so divide that by area and you get linear flow.

acceleration=changevelocity/time so on a per second basis,
acceleartion=newvelocity-oldvelocity
=oldvelocity((7.5/.8)^2-1)

and then, Force=mass/second*acceleration
= density*450L/60sec*acceleratin

check my thinking.

Answer this Question

Related Questions

momentum and it's conservation physics - when a fire hose is hook up to a ...
physics - A fire hose ejects a stream of water at an angle of 31.5 ° above ...
Physics - A fire hose ejects a stream of water at an angle of 29.0° above ...
physics - A fire hose ejects a stream of water at an angle of 38.3 ° above ...
Math - A fire hose has a circular cross-section which has a diameter of 20 cm. ...
physics - A fire hose ejects a stream of water at an angle of 37.9 ° above ...
physics - A fire hose can fill a certain tank with water during 1 hour. A 2nd ...
Physics - A fire hose 3.8 cm in diameter is capable of spraying water at a ...
Eng. Dynamics - A fire fighter is standing 20 m from a burning building as shown...
physics - The pressure in a fire hose is 20 atm. How high can a firefighter ...

For Further Reading

First Name:
School Subject:
Answer: