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Barclay
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Homework Statement
A student designs an experiment to measure how electrically charged a plastic rod is. She knows a charged rod will deflect a stream of water from a tap.
The student plans to measure the angle of defection of the water stream when she brings the rod towards it.
She expects that a negatively charged rod will attract the stream and a positively charged rod will repel the stream.
She expects that the greater the charge the greater the angle of deflection.
Q1. Explain why the student is wrong about using a water stream to tell the difference between positive and negative rods.
Q2. When she "brings the rod to the water" what improvements can be made?
Q3. What is the dependent and independent variables?
Homework Equations
The Attempt at a Solution
A1. The rod will always attract the water (or deflect it) but it will not be different for different rods because the water will be a new fresh steam and the water molecules will rotate so that the stream is attracted for all rods (or deflected).
A2. The rods must be brought to the water at the same speed and at a set distance from the rod and held in position for same time in each case.
A3. Independent variable is the rod. Dependent is the waterCan I ask about a similar experiment with a gold leaf. How do you know if the charge is positive or negative if you can't actually see it. You just have to assume a charge compared to the other rods that induce a charge in a gold leaf
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