Question

While you are driving down a country road at dusk with a velocity of 22 m/s, a deer suddenly runs across the road in front of you. You apply the brakes, reducing your velocity to 7 m/s in 5 s as you avoid hitting the deer. What is the acceleration of the car?

Answer 1

Answer:

$a=\frac{v_{f}-v_{o} }{t_{f}-t_{o} } =\frac{(7-22)\frac{m}{s} }{5s-0s} =-3\frac{m}{s^{2} }$

Explanation:

We know that the initial velocity is 22 m/s

The final velocity after applying the brakes is 7 m/s, and the time that takes it to break is 5 seconds

We know that the concept of acceleration is the change of velocity in time

$a=\frac{v_{f}-v_{o} }{t_{f}-t_{o} } =\frac{(7-22)\frac{m}{s} }{5s-0s} =-3\frac{m}{s^{2} }$

The answer is negative since the car is slowing down