Lab # 1: Electric Charge and Coulombs LawExperiments 1-3Madison McVeyDate: July 11, 2016Running Head: Electric Charge and Coulombs LawAbstract:In this lab, students investigate the nature of electrical interactions using strips of Scotch tape and other common objects found in a classroom environment. Students are able to use Coulomb’s Law and general physics knowledge to predict whether two objects will attract or repel one another or have no electrical interaction. Students will attempt to determine the relationship between distance and the attractive force of two charged objects.Background: 1Running Head: Electric Charge and Coulombs LawThere are two different kinds of charges in this world; they are negative and positive charges. The charges that like each other repel and the charges that unlike each other attract. Coulomb’s law is another essential law in order to understand this experiment better. This is when the force exerted by one charge q on another charge Q is given by the expression: Coulomb's law allows us to predict electric forces between charges, but it does not explain where the forces come from. Methods: - Experiment #1 - Exploring Charge with Scotch® Tape:For part 1, students used the ruler to measure a piece of tape that was 10 cm long and created a handle on one side of the tape that was 1 cm long. Students stuck the entire sticky surface of the tape to a tabletop and repeated steps 1-4 to create a second piece of tape. Students quickly pulled off both strips of tape from the surface of the table and brought the non-sticky sides of the tape together. Students recorded observations about the behavior of the pieces in Table 1 and discarded the tape. For part 2, Students cut 4 pieces of 10 cm tape with a 1 cm handle, labeling the pieces as: T1, B1, T2, and B2, for top 1, bottom 1, top 2, and bottom 2. Laying the top piece on top of its respective bottom piece on the flat tabletop. Students used the T1 handle to quickly pull off T1 strip of tape from the flat surface and used the B1 handle to peel off the bottom strip from the flat surface. They kept both B1 and T1 pieces away from each other and brought the non-sticky sides of B1 and T1 together and recorded observations about the behavior of the pieces in Table 1. They set the pieces of tape, non-sticky side down, on the table approximately 15 cm away from each other, and repeated the process for B2 and T2. Students performed this same trial for T1 and B2, T1 and T2, B1 and B2, T1 and the students arm hair, and B1 and the students arm hair. All observations about the behavior of the pieces were recorded in Table 1. - Experiment #2 - Static Materials:To begin, students tore paper into small pieces, each approximately the size of a hole-punch, and scattered them in a small area on a table or flat surface. They chose one plastic strip, either acetate [wide and clear], vinyl [narrow], or polyethylene [wide and white], and one of fabric, either wool or cotton cloth, from the electrostatics kit. They quickly rubbed the fabricup and down the length of the plastic strip for approximately 20 seconds and brought the plastic strip near the small, torn pieces of paper. Students recorded observations about the amount picked up and behavior of the paper in Table 2 and repeated this process for five additional fabric and plastic combinations.- Experiment #3 – Charging by Contact and Induction: To start, students tore one small piece of masking tape from the roll, approximately 5 cm long, and created a small, closed loop with the tape, leaving the sticky side on the outside of the loop. Students secured the looped tape to one of a side of the wooden block adjacent to 2Running Head: Electric Charge and Coulombs Lawthe side with the slit and pressed the taped side of the wooden block onto a smooth wall (or the flat side of a counter or table top) with the slit pointing perpendicular to the wall and parallel to the floor. They unwraped the outer layer of a paperclip and used the exposed end of the paperclip to poke a hole through the centers of two pith balls. One end of the monofilament line was threaded through one of the pith balls and a knot was tied on the endthat was threaded through to keep the pith ball on the thread. This step was repeated on the other end of the monofilament line with the other pith ball. Once the pith balls were securedon each end of the line, the line was placed in the slit of the wooden block. Students removedany charge from the acetate strip (wide and clear) by grabbing it with their hand and tested for interactions between the acetate strip and both pith balls. They recorded observations ofany interaction. Students charged the acetate strip by rubbing it with the cotton cloth and slowly brought the plastic strip close enough to the right pith ball so that it moved, but did not touch the plastic strip. Once movement of the pith ball was observed. the plastic strip was moved away. Students recorded observations in a note section of their lab notes. Students then slowly brought the plastic strip close enough to the left pith ball so that it moved, but did not touch the plastic strip. Once movement of the pith ball was observed, the plastic strip was moved away and observations were recorded. Next, students held the monofilament line above the right pith ball and brought the ball into contact with the plasticstrip. They let the pith ball hang again and brought the plastic rod close, but without touching the right pith ball, and recorded observations. Students then held the line above the right pith ball and brought it close to the left pith ball, and recorded observations of that interaction. To conclude the experiment, students grabbed the pith balls to ground them andtake away any charge they may have. The plastic rod was charged again with the cotton and the line above the right pith ball held with your pointer and middle finger. The right pith ballwas brought close to the plastic rod, but did not touch. Next, the left side of the ball (the one opposite of the rod) was touched with the student’s thumb and the ball hung again. Studentsfinally brought the right pith ball close to the left pith ball and recorded observations of what occurred. Results: - Experiment #1 - Exploring Charge with Scotch® Tape:The following data table reflects the interactions observed between static charged pieces of tape. Table 1: Electric Charge ObservationsProcedure Interacting Pieces ObservationsPart 1