# Projectile being launched off a table at an angle?

1. The problem statement, all variables and given/known data

We did an experiment where we launched a ball at an initial velocity of 1.80 m/s, at an angle of 10 degrees. We measured the distance in the x-axis the ball travelled 0.743 m. Using this information, we are supposed to calculate a predicted value for the distance in the y-axis (initial height). Since we did the experiment, we have an experimental value of 1.12 m for the height, but my teacher wants us to calculate a predicted value for initial height and compare using absolute % error ((predicted – experimental) / experimental).

2. Relevant equations

x y
vi = (vi)cos(10) vf=(vi)sin(10)
a = 0 a= -9.81
t = ?
dx= 0.743 m dy = ?
3. The attempt at a solution

I calculated vix to be 1.773 m/s and viy to be 0.3125667 m/s. I’m unsure how to calculate time, and also am unsure if there is a vi for y-axis (my teacher said I did the question wrong because I used dy= vit + 1/2at^2 and cancelled out vit because I believed vi was 0 but the ball is being launched so there is a vi for y).

http://ift.tt/1e5awcI