A stone is throne vertically up from the edge of the cliff t

A stone is throne vertically up from the edge of the cliff that has the height of s in feet after t seconds

(a) determine the average velocity after the interval [0,2]

b) determine the instantaneous velocity at t=2 seconds

after time t the stone is at height s

let the initial velocity is u

so from equation of motion s=ut+(1/2 )gt²

(a) average velocity in the interval(0,2)

{S(2)-S(1)} divided by (t2-t1)= (2u-2g)/2=( u-g)

(b) ds/dt= u+gt

instantenous velocity at two second is

v = u+2g

so v=u+2g