Supporting inquiry based teaching and learning. Static Electricity. Class: Student Name:

Transcription

1 Supporting inquiry based teaching and learning Static Electricity Student Name: Class: Teacher Name: School:

2 Question 1 We are electrons. a) What electrical charge do we have? We are protons. What electrical charge do we have? b) Static electricity is caused by the imbalance of positive and negative charges. Material A Material B Material C What is the electrical charge on material A?

3 Give a reason for your answer: What is the electrical charge on material B? Give a reason for your answer: What is the electrical charge on material C? Give a reason for your answer:

4 Question 2 a) A student cut small horses from a piece of folded paper so that they stood on the desk. The student then rubbed a plastic pen with fur. Rubbing plastic with fur results in electrons from the fur being rubbed off onto the plastic. She started to move the pen away from the horses as shown by the arrow. She noticed that the paper horses followed the pen along the desk. Horse A Horse B What electric charge has the plastic pen after it was rubbed with the fur? Why does the paper horse follow the pen? How could the student make horse A move faster than horse B in a race? Would it make a difference if the paper horses were damp?

5 b) A student put two red drinking straws parallel to each other on the bench. The student rubbed the two drinking straws with a woollen cloth. This caused some of the electrons to move from the cloth onto the drinking straws. What electrical charge was now on both straws? The straws rolled away from each other. Suggest a reason why this happened. Write the rule or a statement about charges to explain why the straws rolled away from each other? The student now rubbed a glass rod with a woollen cloth. This caused electrons to be removed from the glass. What electrical charge was now on the glass rod? When the student placed the glass rod near the straws, they rolled towards the glass rod. Why do you think that the straws did this?

6 Question 3 A student is investigating attraction and repulsion in static electricity. He has the pieces of equipment shown below. The student rubbed the rods as shown. What happens 1. when the polythene and perspex rods are brought near each other? 2. when the two charged persex rods are brought near each other? Can you give a rule or law for what happens when charged objects are brought near each other?

7 Question 4 a) Benjamin Franklin flew a kite at the end of a silk string during a lightning storm. There was a key attached to the string, as shown in the picture. Franklin suggested that lightning was the result of a large static electrical charge building up in the atmosphere and jumping to the earth. Kite Key Wire Can you suggest why Franklin used a silk thread to fly the kite? It started to rain. Franklin attached a wire to the key. A spark jumped into the ground? Why did Franklin use a key and a wire? What do you notice about the position of Franklin s hand in the photo? Franklin was lucky to survive this experiment. The next two people to try this experiment were killed. How and why do you think they were killed?

8 Lightning conductor b) How do you think a lightning conductor protects a building in a lightning storm? c) When oil flows through the filler pipe, friction takes place between the flowing oil and the pipe. An oil vapour can also build up. Why do you think the oil tanker must be earthed? d) When a car is in motion a static electric charge can build up on the car. Suggest a reason why this happens. What could be done to the car to prevent the build up of this charge?

9 e) After walking on a carpet, you can sometimes get an electric shock when you touch the metal handle of a door. Why do you think this happens? Who is in more immediate danger if they continue to play during a lightning storm the golfers or the hurlers? Explain your answer: You are in a field during a rain and lightning storm. There is a large oak tree in the middle of the field. Is it better to shelter under the tree or to stay out in the open? Explain your choice: You are advised not to use a landline phone during a thunder storm. Give a reason for this.

10 For teacher use only. Comment: How to improve: