Describe the relationship between a compass and a magnet. Use C. E.R. Your C. E.R should have a one-sentence claim, three pieces of evidence, and two reasoning sentences that explain why you chose your evidence.

ANSWER KEY Relationship of Magnets CER

Claim (Write one sentence stating the cause and effect relationship of magnets.)

In magnets, like poles repel, whereas opposite poles attract.

Evidence (Provide scientific data to support your claim. The evidence should include how attraction and repulsion is demonstrated by the matchbox cars and the position of the poles of the magnets.)

When the North Pole of the magnet (orange) and the South Pole of the magnet (green) came close to one another they attracted and when the North Pole of the magnet (orange) and the North Pole of the magnet (orange) came close to one another, they repelled. The South Pole against the South Pole repelled as well. Therefore confirming that opposite poles attract and like poles repel. We were able to record data to show the distance that each car traveled by using either attraction or repulsion. Four out of five cars give evidence that the repulsion, created by opposing poles, had the stronger force.  

Reasoning (Explain why your evidence supports your claim. Describe how the poles of the magnet determine whether magnets attract or repel and how your evidence allowed you to see the force of the attraction or repulsion.)

Magnets have an invisible force around them, called the magnetic field, which has North and South Poles. The opposite poles attract and like poles repel. We saw this through completing the activity by seeing and measuring the distance that was traveled by each car using attraction and repulsion.

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it

305.7

explanation:

density =m/v

density =917/3.00

density = 305.

approximately = 305.7

in four significant figures