Ready to Launch!

1. Ready to Launch! PHYS 2010 Midterm Project

2. Experiment and Purpose • Our experiment was to determine the distance a projectile will travel when launched from different angles. • We performed the experiment by first attempting to use a homemade catapult and then a launcher premade by the physics department.

3. Let’s get started… • Items needed: 1. catapult or launcher -Your catapult and launcher can be homemade, store bought, or in our case, courtesy of Jimmy in the Physics department. 2. Projectile (ball, penny, etc) 3. Meter stick 4. Protractor 5. Sticky notes (optional) 6. Calculator

4. How it is done… • First, start the launcher at 10°. Carefully measure the angle with the protractor. • Launch and record the data. Repeat 4 more times for this angle. Take the average of the collected data. • Repeat launch for 20°, 30°, 40°, 50°, 60°, 70°, 80°, and 90°. Repeat each launch 5 times for each angle and take the average. • Graph the data and determine which angle had the longest distance. • Calculate uncertainties for the distance and angle.

5. Time to launch! Trial 1 Trial 2 • Homemade catapult used • Angles from 0° to 100° in increments of 10° • One launch per angle • Mass of penny=3.06g • Premade launcher used • Angles from 10° to 90° in increments of 10° • Five launches per angle (average taken) • Mass of ball=2.21g

6. Time to launch! Trial 1 Materials Used Trial 2 Materials Used

7. Trial 1 Data

8. Trial 1 Graph

9. Trial 2 Data

10. Trial 2 Graph

11. Velocity • Vi=√2gHave • Vi=√2(980)(37.6)=271.47 • R=(v2/g)sin(2Θ) • Theoretical: • R=[(271.472 cm/s)/980 cm/s2]sin(2(45°))=75.20cm • R =[(271.472 cm/s)/980 cm/s2]sin(2(60°))=65.13cm • Actual: • 45°≈65cm • 60°≈72.6cm

12. Uncertainties • S(d)=5 cm • S(angle)=5° • Fu(d)=S(d)/dave=5cm/53cm=0.1 • Fu(angle)=S(angle)/angleave=5°/50°=0.1

13. Theory • 45° should be the top angle because it would create a perfect arc. • 90° should be the smallest angle because it is straight in the air so it would have no horizontal. 45° angle 90° angle

14. Data Analysis • Unlike expected, the highest point on the graph was 60° instead of 45°. • This could be because we did not measure the angles properly. • After doing the theoretical distance for 45° and 60°, we found that the expected value for 45° was close to the actual value for 60° • 90° was the smallest distance but it did not equal zero like expected.

15. Conclusion • In conclusion, we used the launcher to demonstrate projectile motion and finding the distance that the projectile will travel when launched from different angles. • Human error can cause unexpected results which we demonstrated in trial 1 of this experiment. • Our expected results did not match the correct angle but we did find that the angle with the largest distance was close to the expected distance for our expected.