Models are often used in science to gain insight into how things work. One of the goals of the laboratory portion of this Topic 7 is to create a polymer ball that bounces high. Use the computer model of an idealized bouncy ball constructed from springs that is available
at http://www.chem.uci.edu/undergraduate/applets/bounce/bounce.htm to investigate how the bounce height is expected to vary with spring constant k (i.e. the elasticity) of the material that makes the ball. (5 points) a. Set the G-slider to a value of 0.010 units and then select a value of K in the range of 0.4-5.0. Click on the go button and allow the ball to bounce 3 times. When the ball reaches the peak of the third bounce, click stop and use a ruler to measure the distance between the floor of the simulation and the center of the ball. Click on the reset button and repeat a similar measurement with a new value of K. Create a table summarizing at least 5 such measurements. Your data table should have a title and column labels (including units if appropriate.) b. Construct a graph summarizing your results. The graph should occupy at least half of a page, should have the controlled variable on the x-axis, the measured experimental value on the y-axis, a descriptive title, and labels including units. A symbol should be used for each data point and a smooth curve or line can be hand drawn to show the general trend of the data. (Do not simply connect the points like dot-to-dot.) c. Based on your data, what theoretical explanation can you propose for the reason the ball does not bounce forever and the reason the bounce height depends on the spring constant? (Hint: you may want to click on the energy button during one of the simulations, where COM= potential energy of the center of mass, ROT= rotational energy, and INT= internal vibrational energy.) Topic 7 19B d. Based on your explanation in part c, what do you think will be the general trend between the number of chemical cross-links that you will synthesize and the resulting bounce height of the ball?