## During a rain storm, rain comes straight down with a velocity Vi = -15 m/s

During a rain storm, rain comes straight down with a velocity Vi = -15 m/s and hits the roof of a car perpendicularly. The mass of the rain per second that strikes the roof is 0.060 kg every second. Assuming that the rain comes to rest upon striking the car (Vf = 0 m/s), find the average force exerted by the rain on the roof during a 3 second time interval.

## Answer ( 1 )

Force is change in momentum of rain = 0.06 * 15 = 0.9 N

The answer would remain same for any time interval since its asked average.

I used m *change in velocity per unit time = 0.06 kg/sec * 15 m/s = 0.9N