Assume you are speeding down the freeway at 75 mph. The car in front of you takes 3 seconds to slow down. Your initial velocity is 33.53 and your final velocity is 0. If your reaction time is 1.6 seconds, how long will it take to slow down? In meters and seconds. Additionally, the car weighs 1500 kg and the effective force of the brakes is 14400 N.
Answers (1)
This is a very easy question for physics. There're what you need to know: Newton's 2nd Law and the relationship between the acceleration and time interval. By knowing that the opposite force (brake) is a constant, we know that it is a constant acceleration question. Sum of force=mass * acceleration. So, -14,400N=1500kg* a => a=-9.6m/s^2. Then, time interval = (final velocity - initial velocity) / acceleration +1.6s = 5.07s, which is the final answer.