- #1

- 25

- 0

## Homework Statement

A physics student on Planet Exidor throws a ball, and it follows the parabolic trajectory shown. The ball's position is shown at 1.00 s intervals until t=3.00 s. At t=1.00 s, the ball's velocity is v=(2.73i+1.78j) m/s. Determine the ball's velocity at t=0.00 s. (Enter your answer in component form. Input the x-component first, followed by the y-component.)

http://capa.physics.mcmaster.ca/figures/kn/Graph06/kn-pic0608.png [Broken]

## Homework Equations

I know that v0x=vcos∅ and v0y=vsin∅

## The Attempt at a Solution

I'm not sure how to begin without being provided with the launch angle. I tried to find the angle using the given velocities (at t=1 s), using tan

^{-1}= vy/vx=1.78/2.73, which gave me 33.1. But this angle, at t=1, will not be the same as the launch angle, right?

Last edited by a moderator: