Why was glass or plastic used to separate the filings from the magnets in the experiments?
the experiment required me to place a bar magnet on a table, then place a sheet of glass or plastic over the magnet before sprinkling the filings over it. i had to do this for both a bar magnet and a horseshoe magnet.

In a vernier instrument the main scale is in 1/2 mm divisions .vernier is made by redividing 19 such divisions into 20 equal parts. calculate the least count of the instrument.

A30 kg weight lies on top of a massless piston of area a = 0.01 m2 the exterior air is at a (constant) p =1 atm and t = 27 c. the interior gas is 0.4 moles of (ideal) n2 and it has initial temperature 27.00 degrees c. 1. what is the initial pressure in the interior? a. 29.4 kpa b. 130.7 kpa c. 101.3 kpa the next three questions concern what happens when an amount of heat q is slowly added to the interior, raising the piston by 1 mm and raising the interior temperature to 27.40 c

How is the gravitational force related to the distance between two objects?