4. The electric force between electric charges is much larger than the gravitational forces between charges. Why, then, is the gravitational force
between the Earth and the Moon much larger than the electric force between
them?*
A. The electric force is small in comparison because charges are VERY small but the
gravitational force has to do with the mass of the Earth and Moon.
B. The electric charge is actually greater and the question is false.
C. The phases of the Moon determine the amount of electric and gravitational force.

16. a brave but inadequate rugby player is being pushed backward by an opposing player who is exerting a force of 800 n on him. the mass of the losing player plus equipment is 90.0 kg, and he is accelerating at 1.20m/s2 size 12{1 "." "20"" m/s" rsup { size 8{2} } } {} backward. (a) what is the force of friction between the losing player’s feet and the grass? (b) what force does the winning player exert on the ground to move forward if his mass plus equipment is 110 kg? (c) draw a sketch of the situation showing the system of interest used to solve each part. for this situation, draw a free-body diagram and write the net force equation.