Projectile Motion Problem

by mst3kjunkie
Tags: motion, projectile
mst3kjunkie is offline
Sep27-06, 04:57 PM
P: 16
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

ay=-g m/s^2


Thank you in advance.
Phys.Org News Partner Science news on
Cougars' diverse diet helped them survive the Pleistocene mass extinction
Cyber risks can cause disruption on scale of 2008 crisis, study says
Mantis shrimp stronger than airplanes
Doc Al
Doc Al is online now
Sep27-06, 05:04 PM
Doc Al's Avatar
P: 40,905
Treat the vertical and horizontal components separately. Hints: What's the vertical component of velocity at the highest point? (t = 2) What about the horizontal component?
mst3kjunkie is offline
Sep27-06, 05:21 PM
P: 16
Figured it out. since the velocity in the y direction is 0m/s at t=2s, I was able to calculate the gravity. I then used this to find the velocities at the other times. I don't know if using part b to solve part a is correct, but I can check my instructor's webpage to see if it gets the correct answer.

Register to reply

Related Discussions
Projectile Motion Problem Introductory Physics Homework 3
Projectile Motion Problem Introductory Physics Homework 4
Projectile Motion + Linear Motion = Problem Introductory Physics Homework 3
Uniform Circualr Motion with Projectile Motion problem (Extremely confusing): Introductory Physics Homework 4