Multiple choice
since a unit positive charge is used to measure an electric field, what would be an appropriate test object to measure a magnetic field?
a) a single south-seeking pole of unit strength
b) a north-seeking pole of unit strength with a south-seeking pole of the same strength
c) a single north-seeking pole
d) a single north-seeking pole of unit strength

It is may 5 and you are somewhere in the northern hemisphere. if you determine that the noon sun is 51 degrees above your southern horizon, what is the latitude of your location

Balloon a has charge q, and identical mass balloon b has charge 10q. you hang them from threads near each other. choose all of the statements with which you agree. check all that apply. a. a and b exert the same magnitude forces on each other. b. the force that a exerts on b is 10 times the force that b exerts on a. c. the angle between the thread supporting a and the vertical is < the angle between the thread supporting b and the vertical. d. the force that a exerts on b is 1/10 the force that b exerts on a.

Arigid tank is divided into two equal parts by a partition. one part of the tank contains 3 kg of compressed liquid water at 400 kpa and 60°c while the other part is evacuated. the partition is now removed, and the water expands to fill the entire tank. determine the entropy change of water during this process, if the final pressure in the tank is 40 kpa. use steam tables.