A projectile launching device will be provided. The angle of launch can be set to any value from 0o to 90o. A protractor, meter sticks, carbon paper, tape, plumb bob, and level are also provided. You may ask the instructor for other devices if desired.
Determining the Muzzle Velocity
First, design an experiment to measure the "muzzle" velocity of the projectile launched from the device. This is the speed with which the brass ball leaves the launcher. You should take into consideration the limited space in the laboratory and the accuracy of your method. The simpler the method, the better. It is advised that you make numerous measurements, in order to both ascertain the variability in velocity that is inherent in the launcher and to obtain a reliable average value. Keep a complete record of your data and subsequent calculations.
Where to Put the Bucket
A launch angle (roughly between 30o and 50o) will specified after all groups have completed muzzle velocity measurements. The launcher will be located on the floor and a bucket will be place on a pedestal. All groups will have the opportunity to measure the height of the bucket on the pedestal.
Using the equations of motion for projectiles, you will determine the horizontal displacement between the launcher and bucket such that the projectile will land directly in the bucket. Keep complete and clear records of all calculations.
When ready, you will position the launcher and the bucket/pedestal on the floor. You may not make any test trials. Two attempts will be allowed. If the first launch misses, you may make only transverse adjustments to the bucket's position. You cannot alter the horizontal range between the launcher and bucket!
The Report
If the projectile lands in the bucket, you will immediately submit all calculations and data to the instructor. Provided the calculations do not contain any serious errors, this will satisfy your group's Lab Report requirements.
If the projectile misses the bucket, you will be required to submit the usual formal Lab Report the following week. (Note: The instructor will look over the submissions from the successful groups. If serious errors are found, the data will be returned and a formal Lab Report will be required.)
In the formal report, describe the method used for determining the muzzle velocity and estimate the error in the average value of the muzzle velocity. Completely describe all measurements and calculations you made for determining range for the launch. Include diagrams clearly labeling distances, heights and angles. Determine the error in your calculated range from the error in the muzzle velocity, the error in the angle, and the errors in length and height measurements. Compare the error in the range to the width of the bucket.