Warming up on Potential

### This assignment is due before 9 AM, Monday, September 25th, 2000.

Please type your LAST NAME and LAST FOUR SS# digits (eg: Smith3256):

I received no help from anyone on this assignment.

The following three questions refer to the material you were to read in preparation to the lesson. Questions one and two require you to write a three or four sentence response. Number three is a multiple choice question. Click in the appropriate circle.

You may change your mind as often as you wish. When you are satisfied with your responses, click the SUBMIT HOMEWORK button at the bottom of this page.

WarmUp questions are worth 5 points each towards your "Homework and Web Assignments" score (250 points total).

# 1.

Consider the graph above. This could be the graph of gravitational potential energy vs. radius of orbit for a satellite orbiting the Earth. Could it be electrical the potential energy for a positive charge as a function of radius near another positive charge? How about the potential energy for a negative charge as a function of radius near a positive charge? Could it be the electric potential vs. distance for a positive or a negative charge? Please explain what this could or could not be and why.

# 2.

Estimate the total charge that passes through a typical lightbulb in one second.
Hint: Assume that the voltage across the bulb is 120 V.

# 3.

(A 152 review!) If I lift a bowling ball from the floor and put it on a table, which of the following is true?

I do positive work and the Earth's gravitational field does no work.

The Earth's gravitational field does positive work and I do negative work.

The Earth's gravitational field does positive work and I do positive work.

I do positive work and the Earth's gravitational field does negative work.

I do negative work and the Earth's gravitational field does no work.

Below is a space for your thoughts, including general comments about today's assignment. What was hard or confusing (or cool)? What would you like to spend extra time on in class? Do you see how this subject fits in with the others we have discussed?

You may change your mind as often as you wish. When you are satisfied with your responses click the SUBMIT button.

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