Andrew Rocco

A.P. Lab Procedure

Projectile Motion Lab:

Items-

1. Yellow Launcher Ball
2. Launcher Apparatus
3. Two meter sticks
4. Stop Watch
5. Electric Car
6. Clamp
7. Plunger

Procedure-

1. Set the two meter stick on each side of the toy car so that the car travels in a straight path between the two sticks
2. Start the car’s front wheels at the far end of the meter stick and, using the stopwatch, record the time it takes the car to travel the length of the meter stick, stopping once the front of the car reaches the end.
3. Record the time and using the distance, 1 meter, calculate the velocity of the car. This will allow you to later calculate the time to x needed to hit the car with the ball.
4. Set up the launcher at the very edge of the science desk so that the front base of the launcher is right at the edge.  The clamp will secure the launcher so recoil is negligible.
5. From various angles launch the ball out of the tube, using the stopwatch to record time to when it hits the floor.  Leave the meter sticks aligned on the floor so you can measure the distance traveled and have a spotter waiting to watch for where the ball initially hits.  Remember to measure the elevation of the lab table from which the ball is shot using the meter stick. Using this data, calculate the initial velocity of the yellow ball as it is shot out of the launcher.
6. Now, with the different velocities from the different launch angles calculate the vertical and horizontal components from each angle, then average the horizontals and verticals to get the average velocities for the two components.
7. Using the initial velocity of the ball, velocity of the car, height, and distance traveled, calculate the angle of which to ball needs to be shot so that it hits the car as it travels away using the data collected in VPython. (Point of impact will be given by the teacher)

 

 

Data Collection:

Hit the Buggy! CAR #5 LAUNCHER #2

2.44 seconds/m

v=0.40983606557377049180327868852459 m/s

0 degrees

2.42 meters

.32 seconds

2.36 meters

.43 seconds

 

31.6 degrees

3.35 meters

.69 seconds

3.32 meters

.66 seconds

 

45.2 degrees

3.21 meters

.82 seconds

3.19 meters

.91 seconds

3.20 meters

.81 seconds

 

61.8 degrees

2.5 meters

.94 seconds

2.52 meters

.97 seconds

 

   We used both the Computational Model and the formula to find the needed angle of launch, but the model was our primary.  We set in our initial velocities and height and distance into the model and ran a special set up for it so that it would run various angles at the same time till one hit exactly three meters.

Conclusion: What ended up occurring was we fell short of the target by half of a meter exactly.  We decided to use Kavinda’s equation to solve for the angle needed to hit the car and got the same angle plus another one.  That second angle was the one that worked sadly.  The only reason our group concluded to be the source of the short fall of our ball was that we had the wrong initial velocity of the ball.  It would have been wiser to take a shot at 45 degrees then calculate the velocities rather than have a bunch of random ones which gave too much uncertainty.