Question

(I) A car slows down from 28 m????s to rest in a distance of 88 m. What was its acceleration, assumed constant?

Answer 1

Answer:

The  value is  $a = - 4.45 m/s^2$

Explanation:

From the question we are told that  

       The  initial speed is  $u = 28 \ m/s$ at a distance of  $s_1 = 0 \ m$

        The  final speed is  $v = 0 \ m/s$    at a distance of  $s_2 = 88 \ m$

Generally  from the  kinematic equation we have that

       $v^2 = u^2 +2as$

=>   $a = \frac{v^2 - u^2 }{ 2(s_2 - s_1 )}$

=>  $a = \frac{0 - 28^2 }{ 2(88 - 0 )}$

=>   $a = - 4.45 m/s^2$

The negative sign shows that it is decelerating