Name ____________________________________Electric Fields Go to http://phet. colorado. edu/simulations/sims. php? sim=Electric_Field_Hockey and click on Run Now. 1. You rub balloons in your hair and then hang them like in the picture below. Explain why you think they move apart and what might affect how far apart they get. A balloon becomes negatively charged when it is rubbed on a person’s hair.
This occurs because all the protons and neutrons leave the balloon and attach to other objects such as the hair. If two balloons both have negative charges then both balloons will repel each other because same charges repel while opposites attract. 2. Test your ideas using Electric Field Hockey in the Practice mode. Make a table to record your observations about what affects the direction and speed of the puck. Your table should demonstrate that you have run controlled tests with all the variables. Charges introduced |Effects on positive charge repulsion | |Positive |Repel | |Negative |Attract | Charges introduced |Effects on positive charge speed | |Positive |Close to charge=Increasing repulsion speed | | |Far from charge= decreasing repulsion speed | |Negative |Close to charge=Increasing attraction speed | | Far from charge= decreasing attraction speed | 3. Reflect on your ideas from question #1 and your data from question #2. How do your observations support, dispute or add to your ideas about what affects how charged bodies interact? The data collected helps support my claims that like charges repel each other while opposites attract. In the case of the balloons both balloons are negative there for repelling each other. 4. As you put charges onto the playing area, arrows appear on the puck. • What do you think the arrows on the puck are illustrating?
The arrows illustrate the movement of the pucks as well as velocity. • How do the arrows from the positive charges compare and contrast to the ones from the negative balls? The positive charges seem to repel the puck while the negatives attract. • Investigate how you can use the arrows to predict the motion of the puck. 5. Write an explanation of how you can predict the motion of a charged hockey puck that is moved by other charged pucks. Explain using examples and drawings that include: • How to use free body diagrams and vector addition. • How negative and positive charges compare and contrast.