An 1800 kg car traveling at 35.0 m/s strikes a wall. If the car comes to rest in 0.500 seconds, then the magnitude of the average force of the wall on the car is

Question

Quizplus · Accepted Answer

We can use the equation F = ma (where a = change in velocity / time) to find the average force of the wall on the car.

First, we need to find the change in velocity of the car:

change in velocity = final velocity - initial velocity 
final velocity = 0 m/s (since the car comes to rest) 
initial velocity = 35.0 m/s

change in velocity = 0 m/s - 35.0 m/s = -35.0 m/s

Next, we can plug in the values we know to find the average force:

F = ma 
m = 1800 kg (mass of the car) 
a = change in velocity / time = (-35.0 m/s) / (0.500 s) = -70.0 m/s^2 (note that the negative sign indicates the direction of the acceleration, which is opposite to the initial velocity of the car)

F = (1800 kg)(-70.0 m/s^2) = -126000 N

The negative sign in the answer indicates that the force of the wall on the car is in the opposite direction to the initial motion of the car (since the car is decelerating to a stop). However, we only want the magnitude of the force, so we take the absolute value:

|F| = |-126000 N| = 126000 N

Therefore, the magnitude of the average force of the wall on the car is 1.26 x 10^5 N, which corresponds to choice C.

An 1800 Kg Car Traveling at 35