suvat question.
answer + detailed explanation needed

4 s

-24.5 m/s

Explanation:

y = y₀ + v₀ t + ½ at²

v = at + v₀

where y is the final position,

y₀ is the initial position,

v₀ is the initial velocity,

a is the acceleration,

and t is time.

Given:

y = 0 m

y₀ = 19.6 m

v₀ = 14.7 m/s

g = -9.8 m/s²

Find: t, v

Substitute values into the first equation and find t:

y = y₀ + v₀ t + ½ at²

0 = 19.6 + 14.7 t + ½ (-9.8) t²

0 = 19.6 + 14.7 t − 4.9 t²

0 = t² − 3 t − 4

0 = (t − 4) (t + 1)

t = -1 or 4

Since t must be positive, t = 4 seconds.

Now use the second equation to find v:

v = at + v₀

v = (-9.8) (4) + 14.7

v = -24.5

less than one you can't create energy