Charges of +3 µC and –5 µC are 2 mm from each other. The –5 µC charge is replaced with a +5 µC charge. How will the electrical force between the charges compare with the original force?
same force, but in the opposite direction
same force, but in the same direction
greater force, but in the opposite direction
greater force, but in the same direction

You throw a baseball directly upward at time t = 0 at an initial speed of 12.3 m/s. what is the maximum height the ball reaches above where it leaves your hand? at what times does the ball pass through half the maximum height? ignore air resistance and take g = 9.80 m/s2.

Air initially at 0.75 bar, 1000 k, and occupying a volume of 0.12 m^3 undergoes two processes. process 1-2: the air is compressed isothermally until the volume is halved. process 2-3: the air undergoes a constant pressure process until the volume is halved again. assume ideal gas behavior. a) determine the mass of the air, in kg. b) the work and the heat transfer for each of the two processes, in kj. (100 kj = 1 bar . m^3)

Find the magnetic field a distance r from the center of a long wire that has radius a and carries a uniform current per unit area j in the positive z direction.