The Coulomb's law is valid for the charges which are (a) moving and point charges
(b) moving and non-point charges
(c) stationary and point charges
(d) stationary and large size charges

The air that we breath is made mostly of which gaseous molecule

Why are graphs useful when interpreting data

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.