The diagram shows the electric field around two charged
objects.
what is the best conclusion about the charges that can be
made based on the diagram?
a. y is negative, and z is positive.
b. y is negative, and z is negative.
c. y and z are like charges, but their identities cannot be
determined.
d. y and z are opposite charges, but their identities cannot
be determined.

Afisherman notices that his boat is moving up and down periodically without any horizontal motion, owing to waves on the surface of the water. it takes a time of 2.20 s for the boat to travel from its highest point to its lowest, a total distance of 0.670 m . the fisherman sees that the wave crests are spaced a horizontal distance of 5.80 m apart. (a) how much is the wavelength? (b) find the period of the wave. (c) how fast are the waves traveling? (d) what is the amplitude a of each wave?