Name: ______ Group Member_________________ Static Electricity When certain types of material such as black vinyl rods, white vinyl strips, plastic combs, and latex balloons are rubbed with cat’s fur, wool, or human hair, these objects become negatively charged. The friction between the two materials (e.g. a balloon and your hair) causes electrons to be removed from the protein molecules of the hair and attach themselves to the molecules of the latex balloon. The balloon retains a net negative charge. When glass rods or acetate strips are rubbed with a piece of silk or cotton, the electrons are stripped off of the glass or acetate and the glass or acetate becomes positively charged. Objective: 1. Students will do a series of activities to investigate the nature of static electric forces. 2. Students will recognize the properties of positive and negative charges. Materials: small, inflated balloon a piece of wool cloth. small bits of paper two 20-cm pieces of string or thread two 6 x 6-cm pieces of aluminum foil 铝片 Scotch Magic TapeTM one coat hanger salt pepper paper plate Procedure: Perform the following steps and record your observations in the space below each step. Draw sketches, use plus signs (+) and minus signs ( - ) whenever possible. You can use “draw” in Word or make drawings by hand and scan them or any other drawing program you want to use. Repeat all steps several times to thoroughly and completely observe the behavior of the static charges. 1. Tear a small piece of paper into very tiny bits. Lay them on the table. Charge an inflated balloon in your hair or with a piece of wool cloth. Slowly bring the balloon near (without touching) the bits of paper. The balloon attracts some bits of paper. 2. Place one of the 20-cm pieces of string on one of the 6 x 6-cm pieces of aluminum foil. Crumple the foil into a ball so the string is caught in the ball. Repeat this with the other piece of foil and piece of string. Suspend the two foil spheres from a coat hanger. Charge the balloon and slowly bring it up under the 2 spheres. The two spheres are attracted by the balloon. 3. Move one sphere out of the way leaving only one sphere hanging. Bring the charged balloon near the one hanging sphere. Do not let the balloon touch the sphere. 4. Now let the charged balloon touch the sphere. When the balloon touched the sphere, the negative charges move to the sphere, so now they have the same charge, then the sphere will be “pushed” and jumped away by the repulsive force. With a partner, stick two 6-inch pieces of c tape together, sticky side to non-sticky side as directed below…. • Take two 15-cm pieces of Scotch Magic TapeTM and fold a 1-cm tab on both ends of each piece of tape. • Stick one piece of tape to your desk. Write the letter “B” for “bottom piece” on one of the tabs. • Stick the other piece of tape on top of the piece already on the table. Mark one of these tabs with the letter “T” for “top piece” • You now have a “tape sandwich”. • Holding only the tab marked “B”, pull the “tape sandwich” off the table. Do this very slowly. • At arms length hold the tab “T” between the finger and thumb of one hand and the tab “B” between the finger and the thumb of the other hand. Quickly rip the two pieces apart. • You now have two oppositely charged pieces of tape. • Slowly and carefully bring them near each other. • Record observations. • Using another pair of charged pieces of tape, compare two “B” pieces of tape. Another tape has negative charges on the “B” pieces while this tape has positive electrons on “B”. • Compare the two “T” pieces of tape. The two “T” pieces both has the negative charges. • Record observations. 5. Since the two piec es of tape were stuck together sticky side to non-sticky side, ripping them apart means that either the sticky stuff on one piece of tape lost or gained electrons or the acetate side of the other piece of tape gained or lost electrons. • Using the charged balloon test the electrification of the two pieces of tape. • “T” pieces of tape are charged ___negative__________. Therefore, the “T” pieces ___outflow_________ electrons. • “B” pieces of tape are charged ___positive__________. Therefore, the “B” pieces ___inflow_________ electrons. (The two pieces of tape can be “recharged”!!! Just stick them together again sticky side to non-sticky side on the table. Pull them off the table together and rip them apart.) 6. Start the water running from a faucet. Adjust the flow so as to produce a narrow, steady stream (no dripping). Charge the balloon and bring it near the stream of water. Do not let the balloon touch the stream of water. 7. Describe what happened and draw a sketch of the result. The stream became curved and the curved part bulged to the balloon because of the attraction force of the balloon. Analysis 1. Based on all of these observations, state some basic rules for the behavior of electric charges. 1) The electrons current from negative pole to positive pole. 2) When something has electric charges, they can attract some light and small things. 3）Like charges repel, unlike charges attract. 2. Sprinkle equal amounts of salt and pepper lightly on a paper plate. Charge a balloon in your hair or with a wool cloth. Hold the charge balloon high over the mixture of salt and pepper. Slowly bring the balloon closer to the mixture. Record observations. Write a short narrative in your own words to explain what happened and why. When the balloon friction on my hair, it produced negative charges. And then the balloon attracts pepper, because of pepper is very light, and it has positive charges, so it can attract. But the salt has a little weight, so I think it doesn’t work. Static Electricity Name: Group Members (if any): Instructions: When certain types of material such as black vinyl rods, white vinyl strips, plastic combs, and latex balloons are rubbe with cat’s fur, wool, or human hair, these objects become negatively charged. The friction between the two materials ( a balloon and your hair) causes electrons to be removed from the protein molecules of the hair and attach themselves the molecules of the latex balloon. The balloon retains a net negative charge. When glass rods or acetate strips are rubbed with a piece of silk or cotton, the electrons are stripped off of the glass o Outcomes: 1. Students will do a series of activities to investigate the nature of static electric forces. 2. Students will identify the properties of positive and negative charges. Materials: 1 Small Inflated Balloon 1 Piece of Wool Cloth Small Bits of Paper 2 20cm Pieces of String or Thread 2 6 x 6cm Pieces of Aluminum Foil 1 Scotch Magic Tape 1 Coat Hanger Salt Pepper 1 Paper Plate 1 Camera or phone to take a selfie with your setup. Safety Points: 1. Small parts are involved, keep them from small children or animals. 2. Avoid swinging the coat hanger around the space. Procedure: Perform the following steps and record your observations in the space below each step. You must also take a selfie of you with your setup to make the measurements. Your face must be visible in the picture. Insert i Paste drawings or pictures in this report. Use plus signs (+) and minus signs ( - ) whenever possible. You can use google drawin Repeat all steps several times to thoroughly and completely observe the behavior of the static charges. 1. Tear a small piece of paper into very tiny bits. Lay them on the table. Charge an inflated balloon in your hair or with a piece of 2. Place one of the 20 cm pieces of string on one of the 6 x 6 cm pieces of aluminum foil. Crumple the foil into a ball so the strin 3. Move one sphere out of the way leaving only one sphere hanging. Bring the charged balloon near the one hanging sphere. Do touch the sphere. 4. Now let the charged balloon touch the sphere. With a partner, stick two 6 inch pieces of Scotch Magic Tape tape together, sticky side to non-sticky side as directed below: • Take two 15 cm pieces of Scotch Magic Tape and fold a 1 cm tab on both ends of each piece of tape. • Stick one piece of tape to your desk. Write the letter “B” for “bottom piece” on one of the tabs. • Stick the other piece of tape on top of the piece already on the table. Mark one of these tabs with the letter “T” • You now have a “tape sandwich”. • Holding only the tab marked “B”, pull the “tape sandwich” off the table. Do this very slowly. • At arms length hold the tab “T” between the finger and thumb of one hand and the tab “B” between the finger • You now have two oppositely charged pieces of tape. • Slowly and carefully bring them near each other. • Record observations. • Using another pair of charged pieces of tape, compare two “B” pieces of tape. • Compare the two “T” pieces of tape. • Record observations. 6. Since the two pieces of tape were stuck together sticky side to non-sticky side, ripping them apart means that either the sticky • Using the charged balloon test the electrification of the two pieces of tape. "T" pieces of tape are charged Therefore, the "T" pieces • "B" pieces of tape are charged Therefore, the "B" pieces • (The two pieces of tape can be “recharged”!!! Just stick them together again sticky side to non-sticky side on the table. Pull them 7. Start the water running from a faucet. Adjust the flow so as to produce a narrow, steady stream (no dripping). Charge the ball Analysis: 1. Based on all of these observations, state some basic rules for the behavior of electric charges. 2. Sprinkle equal amounts of salt and pepper lightly on a paper plate. Charge a balloon in your hair or with a wool cloth. Hold the 3. Add your selfie below. and latex balloons are rubbed n between the two materials (e.g. e hair and attach themselves to are stripped off of the glass or be visible in the picture. Insert it at the end of the lab. ble. You can use google drawings or make drawings arges. n in your hair or with a piece of wool cloth. Slowly le the foil into a ball so the string is caught in the ball. ear the one hanging sphere. Do not let the balloon cky side as directed below: s of each piece of tape. one of the tabs. of these tabs with the letter “T” for “top piece”. very slowly. the tab “B” between the finger and the thumb of the part means that either the sticky stuff on one piece of electrons. electrons. icky side on the table. Pull them off the table together m (no dripping). Charge the balloon and bring it near . air or with a wool cloth. Hold the charge balloon high
Purchase answer to see full attachment