The correct option is C average velocity is 53 m/s
Given, v(t)=4t−t2, we will check if the particle has changed its direction or not within the asked time interval, i.e. the time when velocity of the particle becomes zero.
⇒ 4t−t2=0⇒ t=0,4 sec
Also, we know that
xf−xi=∫t0v(t)dt=∫t0(4t−t2)dt
⇒ xf−xi=2t2−t33
Let particle starts from origin i.e xi=0
So, at t=0,xf=0,
at t=4,xf=2×42−433=96−643=323 m
at t=5,xf=2×52−533=150−1253=253 m
Hence, average velocity is 253×5=53 m/s