Question

A ball is thrown directly downward with an initial speed of 8.30 m/s from a height of 30.2 m. After what time interval does it strike the ground?

Answer 1

\[y=v_{0}t+\frac{ 1 }{2 }a t^{2}\]
Substitute
\[y=30.2\]
\[v_{0}=8.30\]
and
\[a=g=9.8\]
Then you should be able to work out what t is.