Consider this system of charges in the picture, where 2 charges +Q and 2 charges -Q are located, alternated, in the vertices of a square (a is the side).

a) Suppose that one of the -Q charges gets "kicked" and is threw out with a velocity v0, while the other three charges are in a state of rest. If the moving charge has a mass m, what's its velocity at an infinite distance from the other charges (result in the figure)?

b) Suppose that the other -Q charge has a mass m too and is moved away with a velocity v0. When it's at an infinite distance from the +Q charges, its speed is bigger, lesser or equal to the one found in the point a)? Explain.

Arunner is jogging at a steady 3.6 km/hr. when the runner is 2.9 km from the finish line, a bird begins flying from the runner to the finish line at 14.4 km/hr (4 times as fast as the runner). when the bird reaches the finish line, it turns around and flies back to the runner. even though the bird is a dodo, we will assume that it occupies only one point in space, i.e., a zero-length bird. how far does the bird travel? (b) after this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. the bird repeats the back and forth trips until the runner reaches the finish line. how far does the bird travel from the beginning? (i.e. include the distance traveled to the first encounter)

Ascientific blank must be testable and capable of being proven false?

Ryan is examining the energy of the particles in a bar of gold. what is ryan most likely studying?