You serve a volleyball with a mass of 0.5kg. The ball leaves your hand with a speed of 30m/s. What is the kinetic energy?

A5 nc point charge is at the origin and a second 3 nc point charge is on the x-axis at x = 0.8 m. find the magnitude and direction of the electric field on the x-axs at x = 0.2 m. you may express the direction by letting positive field mean the positive x direction

The coulomb's law explains which of the following? select all the force between two charged objects is inversely proportional to the charge on each object. the force between two charged objects is directly proportional to the charge on each object. the force between two charged objects is directly proportional to the distance separating them. the force between two charged objects is inversely proportional to the square of the distance separat coulomb's law is similar to newton's 2nd law. if the force between two objects is f and the charge on both objects is doubled, the new force between the would now be 2f. if the force between two objects is 2f and the distance separating them is doubled, the new force between the objects would now o the be zf.

Can any one me on number 4? i do know that it’s not a cause i gotten that wrong on the first try.