2. A car starts from rest and accelerates uniformly to reach a speed of 21 m/s in 7.0 s. What was the speed of
the object after 2.0 seconds?

speed of object after 2 seconds will be 6 ms⁻¹

Explanation:

Initial velocity = 0

Final Velocity = 21 m/s

Time = 7 sec

We need to find speed of object after 2.0 seconds.

First we will find acceleration using formula:

Putting values:

Now finding speed of object after 2 seconds

The formula used will be:

Putting values of a= 3m/s², t=2 sec and v₀=0 (at rest)

So, speed of object after 2 seconds will be 6 ms⁻¹

b

explanation:

a and b sometimes have a positive value