Draw the velocity-time graph for a ball thrown vertically upwards with a velocity of 49m/s.

Dear student

As v = u+at where u is initial velocity , v is final velocity and a is accelaration
a = -g = -9.8$m{s}^{-2}$
At highest point, v =0
$$\begin{gathered} 0 = 49 - 9.8 \times t \\ \Rightarrow 9.8 \times t = 49 \\ \Rightarrow t = \frac{490}{98} =5s \end{gathered}$$
So, at highest point t = 5s
So, graph of given situation is given below


with regards