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Question 4

3 pts
I am approaching a traffic light at a speed of 135 km/h when I suddenly notice that
the light is red. I slam on my brakes and come to a stop in 4.29 seconds. What is the
acceleration of the car as I screech to a complete stop? (Note that an object that slows down
simply has a negative acceleration.)
& show work please I want to also understand

User Mvvijesh
by
4.9k points

1 Answer

2 votes

Answer:

The deceleration of the car is
\approx -0.065m/s^(2)

Step-by-step explanation:

to solve this, we will have to apply the knowledge that will be got from the equations of motion.

There are several equations of motion, and depending on the parameters given in the problem, we can choose the perfect equation that can best be used to solve the problem.

In this case, since we are given the velocity and time, and we are solving for the acceleration, we will use this formula


v = u +at

where v= final velocity = 0

u = initial velocity = 135Km/h
\approx 0.278 m/s

t= time = 4.29 seconds.


a = (v - u)/(t)


a =(0-0.278)/(4.29) \approx 0.065m/s^(2)

Hence, the deceleration of the car is
\approx -0.065m/s^(2)

User Kodfire
by
5.4k points