Physics 151: Computerized Recitation #0

Gaining Familiarity with Physlets

Guidelines

• This activity will not be graded. It is designed to familiarize you with all of the procedures that will be used on subsequent recitations throughout the term.
• Each recitation will consist of a web-page containing simulations and an accompanying worksheet. Since you are reading this web page you have already found the location on the class web page where the recitation materials will be placed. There is also a worksheet available there that accompanies the web page. However, your instructor will typically have already photocopied that for you when you arrive at recitation. The worksheet will typically be turned in at the end of recitation, however your instructor may choose to modify these procedures if the need arises.
• You should be on a PC preferably using Internet Explorer. The animations are not compatible with Macintosh.
• These activities are designed to emphasize collaborative problem solving. You should have a partner and be working together at one computer. If there is an odd number of students one group of three is allowed. You are encouraged to work with different partners and change partners regularly. However, your recitation instructor may choose to dictate partnerships as the term progresses. Communication with groups at other computers is encouraged as well. Just make sure you are discussing the physical principles and methods involved in solving problems (and not just giving away the final answer) and that all students are getting the opportunity to participate and control the mouse.
• This is the second usage of Physlets in recitation on Physics 151 but we are still making refinements. Please feel encouraged to make suggestions regarding the recitation format. We are interested in your feedback!

Physlets

These recitations will make use of Physlets. Information on Physlets can be found on the Physlet Home Page at Davidson College. Please go to this site and read careully the page labeled About and also make note of the offerings on the Resources page.

Simulation #1: Making Measurements in a Physlet

Within a physlet animation you can use the cursor to make measurements. We will typically assume that the values measured are in meters (and for physlets with a running clock that time is in seconds). Use the cursor to measure the width and height of the rectangle shown in the Physlet below. Record these values on your worksheet and then use them to calculate the quantities requested on the worksheet.

Simulation #2: Controling Time in a Physlet

The Physlet below illustrates a ball being tossed in the air. The position of the ball is updated every 0.1 seconds and a ghost image is left in the path of the ball every 0.3 s. A series of buttons (play, pause, step backward, step forward, and reset ) can be used to control the simulation. For most simulations involving time there will be a button labeled "Simulate!" that one needs to click to start the simulation for the first time.

Simulation #3: Data Connections

Physlets allow you to have data from the simulation displayed in a table (or on a graph) which is implemented below for a falling object. Note that there is some delay in the data connection getting the data from the Physlet so that the first time interval does not begin at 0.00 seconds. This animation is configured to run only one and then an "End of Animation" message appears. The reset button can be used to run the animation again.

The data connections lists the time, y-position, y-velocity, and y-acceleration for the falling ball. Since the acceleration is not -9.8 m/s², this simulation does not represent a ball falling on the earth.

Simulation #4: Real World Problems

Three balls are thrown off the top of a building, all with the same speed but different launch angles (position is in meters and time is in seconds). Rank the three balls according to which one hits the ground first and which one has the greatest speed upon impact with the ground.

It isn't important that you get the correct answer to this problem - it is important that you develop a healthy communication with your partner(s) (and other groups) and make use of your real-world experience in problem solving.