CP Physics Lab
Prediction of Trajectories
Objectives: Determine how the vertical distance is related to the horizontal distance when the ball is launched horizontally from a table.
Materials: A ramp, a steel ball, a meter stick, and a target.
Theory:
The range is the horizontal distance, x, between the end of the table
and the place where the ball hits, and is given by x = vx t,
where vx is the initial speed of the ball as it leaves the table
and t is the time of flight. The diagram shows a ball launched at an
angle.
If the ball is shot horizontally (like yours will be), the time of flight of the ball will be t = x/v.
The vertical distance, y, that the ball falls in time t is given by y = 1/2 g t2.
where g is the acceleration of gravity. Using the time t from from the
y equation, you can calculate x using the x equation.
Procedures
1. Set up the ramp on some books so that the ball will roll at a steady rate off the end of the table (it needs to roll about 30 cm on the flat surface of the table before rolling off the end).
2. Make sure to release the ball from the same point every time and not to move the ramp (you can use tape to mark locations).
3. DO NOT ALLOW YOUR BALL TO HIT THE GROUND UNTIL A TEACHER IS WATCHING!
4. Make all necessary measurements to determine the landing position of your ball. Show these calculations to your teacher.
5. The teacher will give you a target to place on the ground. Place the target on the ground and then place a piece of carbon paper over the target. With the teacher watching let the ball roll off the table. You are only allowed ONE trial.
6. Measure the horizontal distance from the end of the table to the
place the ball actually landed and calculate your percent relative error.
Questions to include in your RERUN.
1. What ring did your ball land in?
2. What was your percent relative error? What were some of your sources of error?