When you jump up, you exert an action force on the ground. What's the reaction force? A. your weight B. Earth's gravity C. the ground pushing on you D. your body moving upward

Answer-

a-your weight

Explanation:

Due to Newton's third law of motion when you jump, your legs apply a force to the ground, and the ground applies and equal and opposite reaction force that propels you into the air.

a small object of mass 3.66 g and charge -17.6 µc is suspended motionless above the ground when immersed in a uniform electric field perpendicular to the ground. what are the magnitude and direction of the electric field?

one "light year" is the distance that light travels, through vacuum, in one julian year.   that's 365.25 days, of 24 hours each.