Find force exerted by the water on the glass.?
A car wash nozzle directs a steady stream of water at 1.5 kg/s, with a speed of 30 m/s, against a car window. What force does the water exert on the glass? Assume the water does not splash back.
A car wash nozzle directs a steady stream of water at 1.5 kg/s, with a speed of 30 m/s, against a car window. What force does the water exert on the glass? Assume the water does not splash back.
DawnsAwaken
on November 30th, -0001
For this question all you need to pay attention to is the units. The unit for Force is called the Newton! This can be broken down into:
kg m/s^2
You can get this unit many different ways, you can get it by multiplying mass and acceleration, or dividing velocity squared by distance and multiplying by mass, or even mutliply arbitrary measurements like 1.5 kg/s with 30 m/s. When you multiply these two numbers together you get newtons!!! Cool huh? So all you need to do is multiply them together:
1.5 kg/s * 30 m/s = 45 kg m/s^2 = 45 Newtons!
Bluberry
on November 30th, -0001
Force = delta mv = mv)final – mv)initial, in the direction of the water stream. But there’s no splashback, so vfinal = mv)final = 0.
So, F = – mv)initial = 1.5 kg/s x (-30) m/s = – 45 N. The force acts in a direction opposite to v initial, so it is negative.