Science+Group+3

Bing Tian, Yanling Shi
 * Names of Experiment Designers**
 * Names of the Peer Reviewers** (collaborating group):


 * Names of the Investigators** (those that will conduct the experiment):

Part 1. Design of a projectile motion experiment
A. What is your hypothesis? (You will test one variable with and without air resistance.) The horizontal range is directly proportional to the mass of the projectile if the projection angle, initial velocity and the diameter of the golfball are constant and air resistance is ignored.

B. Create a step by step experimental protocol to test your hypothesis using the applet at: http://phet.colorado.edu/sims/projectile-motion/projectile-motion_en.html You will test one variable with and without air resistance.

- What are the independent vs. the dependent variables in the experiment? - How will you test air resistance in the experiment after testing your initial variable? How do the two variables interact? - How many repetitions will you need to carry out within the experiment? - What data will you collect nd how will you collect it?
 * In your experimental protocol you may wish to ask yourself the following:**

C. Experimental Protocol: step1 go to the website http://phet.colorado.edu/sims/projectile-motion/projectile-motion_en.html click the button "visit"

step2 look at the column "user choice" .click the "golfball" and keep the other items unchanged.NOTE,don't put a check mark before "air resistance". step3 click "fire".when the movie is finished, record the range. step4 change the mass of golfball in a reasonable range, and keep other items constant.click "fire" and record the range again. step5 repeat step 4 four times and you get six sets of readings of mass and horizontal range. step6 draw a graph of horizontal range against mass to see if it is a straight line(with a specific gradient,not zero,not ifinite large ).if YES, my hypothesis is valid, otherwise unvalid.

Part 2. Peer review of experimental protocol.
A. The peer review group should enter their comments regarding the experimental protocol below. They should ask themselves: - Is the hypothesis being careful tested? - Is the protocol easy to follow? Is it sequential? - Can the independent and dependent variables be easily identified and measured?


 * Peer Review:**

B. The experimental designers should now alter the experimental protocol based upon peer review.

Part 3. Conduct the experiment.
Now a different group will conduct the actual experiment using: @http://phet.colorado.edu/sims/projectile-motion/projectile-motion_en.html

A. The investigational group should try to follow the protocol as written. Changes can be made if the protocol is not clear. The hypothesis is not valid. The horizontal range is independent of the mass of the golfball if all other parameters are remains constant.

B. Data should be entered below. Tables for data can be made using the wiki. Simple graphs can be created using MS Office if time allows.
 * mass(g) || horizontal range (m) ||
 * 0.046 || 11.5 ||
 * 0.036 || 11.5 ||
 * 0.026 || 11.5 ||
 * 0.056 || 11.5 ||
 * 0.066 || 11.5 ||

Part 4. Results and Discussion
The investigational group should now write a short paragraph using scientific writing to explain their findings. Findings will be discussed with the group at large.