A body starts moving from rest on a smooth horizontal surface. The acceleration, a, of the body is given by the equation ( t  1) m/s^{2} , where t is the time elapsed in seconds from the start. Determine its average velocity at t = 5 s. a) v = 7.50 m / s 

Since the acceleration
is a function of time, the velocity is given by, The displacement from
the initial position is given by, At t = 5 s the displacement
is given by,. The average velocity
is given by Hence the average velocity is 1.67 m/s. 