During a rain storm, rain comes straight down with a velocity -15 m/s and hits the roof of a car perpendicularly. The mass of the rain per second that strikes the roof is .060 kg every second. Assuming that the rain cones to rest upon stiking the car (Vf =0m/s), fund the average force exerted by the rain on the roof during a 3 second time interval.
force*time=change (mass*velcocity)
force*3=.060*3*15
solve for force.
To find the average force exerted by the rain on the roof, we can use Newton's second law of motion, which states that force (F) equals the change in momentum (Δp) divided by the change in time (Δt):
F = Δp / Δt
Momentum (p) is defined as the product of mass and velocity:
p = m * v
Given that the velocity of the rain is -15 m/s (negative sign indicates downward direction) and the mass of rain per second is 0.060 kg/s.
Now, let's calculate the initial momentum (p_initial) and final momentum (p_final) of the rain droplets during the given 3-second time interval.
p_initial = initial mass * initial velocity
= (0.060 kg/s) * (-15 m/s)
= -0.9 kg⋅m/s
p_final = final mass * final velocity
= 0 kg * 0 m/s (as all rain comes to rest upon striking)
= 0 kg⋅m/s
Now, let's calculate the change in momentum (Δp) during the 3-second time interval:
Δp = p_final - p_initial
= 0 - (-0.9)
= 0.9 kg⋅m/s
Finally, we can calculate the average force (F) exerted by the rain on the roof using Newton's second law:
F = Δp / Δt
= 0.9 kg⋅m/s / 3 s
= 0.3 kg⋅m/s²
Therefore, the average force exerted by the rain on the roof during the 3-second time interval is 0.3 Newtons.