Suppose a 1,600 kg car is traveling at 20.0 m/s. What average force is needed to stop the car in 4.0 s? Can you explain to me how you got your answer, thank you.
(Avg. Force)*(time) = Momentum change
= 1600*20 kg m/s
Avg. Force = 32,000/4.0 = 8000 Newtons
To find the average force needed to stop the car, we can use Newton's second law of motion, which states that force (F) is equal to mass (m) multiplied by acceleration (a). In this case, the acceleration is the change in velocity divided by the change in time.
First, let's calculate the change in velocity. The car is traveling at 20.0 m/s, and we want to bring it to a stop, so its final velocity will be 0. Therefore, the change in velocity (Δv) is equal to the initial velocity (v) minus the final velocity (0):
Δv = v - 0
Δv = 20.0 m/s - 0
Δv = 20.0 m/s
Next, we calculate the acceleration (a) by dividing the change in velocity (Δv) by the change in time (Δt):
a = Δv / Δt
a = 20.0 m/s / 4.0 s
a = 5.0 m/s²
Now that we have the acceleration, we can calculate the force (F) using Newton's second law. The mass (m) of the car is given as 1,600 kg:
F = m * a
F = 1,600 kg * 5.0 m/s²
F = 8,000 N
Therefore, the average force needed to stop the car is 8,000 Newtons.