Q) A bird flies with a speed of v=|t-2|m/s along a straight line , where t is in seconds. What is the distance traveled by the bird during the first 4 seconds?

A)
v=|t-2|m/s
critical point is t = 2
so from t=0 to t=2 , velocity is t-2
and from t=2 to t= 4, velocity is 2 - t
Total distance covered = mod of ( integral (0 to 2) [ t-2] + integral (2 to 4) [ 2 - t] )
= [t^2/2 - 2t] 0 to 2 + [ 2t - t^2/2] 2 to 4
= | -2 - 2 |
= |-4 |
= 4 m ... (since area under graph cannot be negative)

________________________________________________________