Question

A car is alone at a red light. When the lights turn green, it's starts at constant acceleration after traveling 100. M, it's is traveling at 15m/s. What is it's acceleration

Answer 1

The acceleration of the car is 1.125 m/s².

Explanation:

Acceleration refers to the change in velocity of an object per unit time.

There are three basic formulae linking initial velocity ("u"), final velocity ("v"), distance ("s"), time ("t") and acceleration ("a"). They are-

1. v²=u²+2as
2. s =u*t+¹/₂(a*t²)
3. v =u+a*t

All the variable carry the meaning as explained above using formula no 1

Since the car starts from rest (initial velocity "u"=0)

Putting "u"=0 in the formula 1

we get v²=2*a*s

Thus acceleration "a" can be written as a=v²/2s

Putting the value of "v" as 15 m/s and s= 100 m (given in the question)

a=15*15 /(2*100)

a=1.125 m/s²

Thus the acceleration of the car is 1.125 m/s²