:
joe follows the procedure below to make a compass.
1. move a magnet from the top of a needle to its point fifty times.
2. lay the needle on a cork that is floating in a bowl of water.
3. observe the direction that the needle points.
what is the purpose of step 1?
to give the needle an electric charge
to make the needle sharper
to magnetize the needle
to flatten the side of the needle

either a or c, i'm stumped between the two.

to magnetize the needle

Explanation:

The needle is made up of magnetic domains. When we repeat the process of magnet then in that case the torque due to magnetic field on all the domains will align them in one direction.

Due to this phenomenon all domains will give a finite magnetic moment in one direction and this total magnetic moment per unit volume is known as magnetism.

So here we can say that by the repeated process of moving the magnet we have magnetized the needle.

so the correct answer will be

to magnetize the needle

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.