A sprinter accelerates out of the blocks. What force causes his acceleration? A. The runner moves forward

B. The Earth pulling on the runner

C. The runner pushing on the blocks

D. The blocks pushing on the runner

An uncharged nonconductive hollow sphere of radius 18.0 cm surrounds a 12.0 µc charge located at the origin of a cartesian coordinate system. a drill with a radius of 1.00 mm is aligned along the z axis, and a hole is drilled in the sphere. calculate the electric flux through the hole.

Suppose you increase your walking speed from 7 m/s to 13 m/s in a period of 2 s. what is your acceleration?

It is really hard for me right know