Hai điện tích điểm bằng nhau đặt trong chân không cách nhau một khoảng R1 = 4 cm lực đẩy giữa chúng là F1 = 9 nhân 10 mũ trừ 5 niutơn để lực tác dụng giữa chúng là F2 = 1,6 nhân 10 mũ trừ 4 n thì khoảng cách R2 giữa điện tích đó phải bằng bao nhiêu

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.

Abatter hits a 0.140-kg baseball that was approaching him at 30 m/s and, as a result, the ball leaves the bat at 40 m/s in the reverse of its original direction. the ball remains in contact with the bat for 2.0 ms. what is the magnitude of the average force exerted by the bat on the ball?

Two point charges are separated by a certain distance. how does the strength of the electric field produced by the first charge