2 Physics Lab Report 3/12/03 .
Projectile motion had always been a curiosity. Why does the ball not fly in a straight path and off the Earth? That was easily answered by saying that gravity held the object down, but no one really knew the exact path until Galileo solved it. The path is a half Parabola. This is because the velocity in the y direction (Vy) is always increasing while velocity in the x direction (Vx) always remains constant. There are 2 different types of projectile motion. The first in one in which the object starts off traveling only horizontally. The second is when an object is launched at a degree to the horizon. When this is the case the velocity must be broken into its components. Then we work with the same equations as a horizontally launched object: Y=vit + ½gt2 and X= vi*t. When a projectile is launched at an angle Vy is not 0 so we calculate with y as 0. This gives us vit= - ½ gt2 and then v=gt/2 and t=2v/g. When an object is launched horizontally then vi=0 and we get .
Y= ½ gt2 and t2=2y/g and t = (2y/g) ½. For this lab we plugged the time calculated from y into the equation for x getting Vx= X/(2y/g) ½.
Apparatus.
Control ball accelerator.
2 different massed metal balls.
Carbon paper.
Regular paper.
Books.
Procedure.
First we set up the constant accelerator on the table and did a test run with a ball to see approximately where it was going to land. We measured the height of the release and the distance to the carbon paper and paper that we set around the landing site of the ball. We released the ball 5 times recording the distance in the X and repeated for 2 different heights. We then did the same for a different sized ball. After the experiment we calculated the time and average velocity.
Data.
66.2g ball.
Height 109 Height 117 Height 122.5.
X #1 138 X #1 136 X #1 142.
X #2 143 X #2 140.5 X #2 146.
X #3 131 X #3 145 X #3 142.5.
X #4 130 X #4 144.