Warming up on Magnetic Fields

### This assignment is due before 9 AM, Monday, October 16th, 2000.

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.

The force F experienced by a particle with charge q moving with velocityv in a magnetic field B is given by the equation F = q v x B. Of course, the force is zero if the particle is not moving (v = 0), or if there is no magnetic field (B = 0). There are other cases where a particle will not experience any force even when moving in a magnetic field. Please describe these situations.

# 2.

The electron gun in a color TV accelerates the electrons through about 25,000 Volts. Estimate the acceleration of such an electron due to the magnetic field of the earth.

Hint: In Indianapolis, the Earth's magnetic field has a magnitude of about 5.5 X 10-5 T.

# 3.

A proton moving downward enters a region of space with magnetic field B which points eastward. In which direction is the force on the proton?

The force is zero.

The force is to the North

The force is to the South

The force is upward

The force is downward

The force is to the East

The force is to the West

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.

I received no help from anyone on this assignment.

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