Aball rolls from x = - 5m to x = 0m in 1 second . what was its average velocity? (units = m/s) don't forget: velocities and displacements to the right are +, to the left are -

+ 5 m/s

Explanation:

change in displacement = ΔX=final position - initial position

                                            ΔX = 0-(-5) =0+5 =+ 5 m

average velocity =  ΔX/t

                             = +5/1

                             = + 5 m/s

positive sign shows that ball rolls towards right

convex lenses are thicker at the middle. rays of light that pass through the lens are brought closer together (they converge). a convex lens is a converging lens. when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus.