A toy car, initially travelling in a straight line at 30.0 cm/s, slows down with a constant linear acceleration of 3.0 cm/s2. How much time passes before the toy car comes to a halt?

10s

Explanation:

Given parameters:

Initial velocity  = 30cm/s

Acceleration  = 3cm/s²

Unknown:

Time it takes for the car to come to rest  = ?

Solution:

To solve this problem, we apply the right motion equation;

   Our final velocity - 0

So;

       V = U + at

Since the car is slowing down, it will have a negative acceleration

Insert the parameters and solve;

       0 = 30 + (-3) x t

          -30 = -t

              t = 10s