Two spheres have charges -3.1 x 10^-7 C and -3.7 x10^-7 C, respectively. They are separated by a distance of 9.0cm. Calculate the magnitude of the force the two charges exert on each other

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?