Lab Report Projectile Motion

• Purpose

To observe, analyze and compare the theoretical calculations data and actual measurements data of projectile motion.

• Hypothesis

        The displacement value of theoretical calculation is higher than the actual measurement. Due to the air resistance and friction reduced the value of displacement.

• Materials

• A car board
• A marble
• Rulers
• A Photogate (BeeSPIV)
• Two Nelson Physics 12 Textbooks
• An iPhone 6
• A card board box

• Method

1. Put the car board box on the desk.
2. Put one side of the board on the box, another side on the desk directly.
3. Put the Photogate at the end of the board.
4. Put the ruler on the floor, which is perpendicular to the desk.
5. Measure the height of the desk (from the floor) by using the ruler for totally 3 times and determine the average value of the heights measured.
6. Measure the height of the top of the board (from the surface of the desk).
7. Release the marble on the top of the board and make it be able to go through the Photogate.
8. Use the iPhone 6 (slow-motion) to film the process of falling.
9. Check the video and find out the location of landing (actual horizontal displacements).
10. Check the speed of the marble (when the marble is leaving the end of the board) that shows on the Photogate.
11. Record these two data and reset the Photogate.
12. Repeat the step 6 to step 11 for totally 3 times.
13. Add a textbook between the box and the board.
14. Repeat the step 6 to step 11 for totally 3 times.
15. Add one more textbook and measure the new height of the textbooks.
16. Repeat the step 6 to step 11 for totally 3 times.
17. Calculate and determine the average speed and the average actual horizontal displacement of each group of data.
18. Calculate and determine the theoretical horizontal displacement by using the height of the desk and the speed of the marble when it is leaving the board.
19. Compare the actual horizontal displacement theoretical horizontal displacement and analyze the factors that may cause the difference.
20. Make the conclusion.

• Observation

Table height:（1）0.92m （2）0.924m （3）0.923m

                         Average table height:m[pic 1]

Ramp height (none textbook): (1) 0.132m (2) 0.131m (3) 0.132m

                         Average ramp height:m[pic 2]

Ramp height (add one textbook): (1) 0.168m (2) 0.17m (3) 0.163m

                         Average ramp height:m[pic 3]

Ramp height (add two textbooks): (1) 0.198m (2) 0.195m (3) 0.197m

                         Average ramp height:m[pic 4]

Calculation

1.caculate the time

D=[pic 5]

D=[pic 6]

H[pic 7]