A car traveling with an initial velocity of 11m/s accelerates at a constant rate of 2.8 m/s^2 for 4 second what is its velocity at the end of this time

Acceleration can be written as a linear equation:

y=2.8x+11 such that y is velocity and x is time.

Simply plug 4 seconds in for x and solve for y.

y=2.8 (4) + 11

y=11.2+11

y=22.2

The velocity at 4 seconds, therefore, is

22.2 m/s.