8. A Physics student on Planet Exidor throws a ball, and it follows the parabolic trajectory shown in Figure 6.8 (whille it will not be recreated on this forum, the figure shows a part of a parabolic curve which starts at the origin and peaks at t=2. It also shows the velocity vector at t=1, which will be entered later in the pst). The ball's position is shown at 1 s intervals until t=3s. At t=1 s, the ball's velocity is (2.0i + 2.0j)m/s, where i and j are unit vectors. a. determine the ball's velocity at t=0,2,and 3 s. b. what is the value of g on planet Exidor? c. what was the ball's launch angle. I know how to do parts b and c, but can't do either without a. I'm not sure what formula to use, but I do know the following: at t=1: v1=(2.0i + 2.0j)m/s v1x=2.0im/s v1y=2.0jm/s ax=0 ay=-g m/s^2 v1x=v0x=v2x=v3x2.0im/s x0=0m y0=0m Thank you in advance.