X (t) = 20-4t²

then what is average Velocity

in between t = 0 and t=20sec

v = - 80 m/s

Explanation:

Given,

The initial time of a body, t = 0

The final time of the body, t = 20 s

The displacement function of the body is given by the relation,

X (t) = 20 - 4t²

Therefore, the velocity function is by differentiating the above equation with respect to the function 't'

X' (t) = - 8t²

Then,

1) t = 0 s

X' (0) = - 8 (0) ²

= 0 m/s

2) t = 20 s

X' (20) = - 8 (20) ²

= - 160 m/s

The average velocity is given by averaging the initial and final velocity,

V = - 160/2

= - 80 m/s

Hence, the average velocity of the given function is, v = - 80 m/s