A bus moving along a straight line at 20 m/s undergoes an acceleration of 4 m/s². After 2 seconds, its speed will be:

(a) 8 m/s
(b) 12 m/s
(c) 16 m/s
(d) 28 m/s

Acceleration of the moving object is 4 m/s²
Initial velocity is 20 m/s.
Time taken is 2 sec.
By applying 1^st equation of motion we get,
v = u + at
= 20 + 2(4)
= 28 m/s
So, the answer is
(d) 28 m/s