Question

Water from a fire hose is directed horizontally against a wall at a rate of 69.4 kg/s and a speed of 19.6 m/s. Calculate the magnitude of the force exerted on the wall, assuming the water comes to a complete stop when hitting the car, with no splash-back.

Answer 1

Answer:

Force, |F| = 1360.24 N

Explanation:

It is given that,

Water from a fire hose is directed horizontally against a wall at a rate of 69.4 kg/s, $\dfrac{m}{t}=69.4\ kg/s$

Initial speed of the water, u = 19.6 m/s

Finally water comes to stop, v = 0

To find,

The magnitude of the force exerted on the wall.

Solution,

Let F is the force exerted on the wall. The product of mass and acceleration is called the force exerted. Using second law of motion to find it as :

$F=m\dfrac{v-u}{t}$

$F=\dfrac{-mu}{t}$

$F=-69.4\ kg/s\times 19.6\ m/s$

|F| = 1360.24 N

So, the magnitude of the force exerted on the wall is 1360.24 N.