Hai điện tích q1= 4.10-9,q2=-6.10-9 đặt tại 2 điểm cắt nhau 40 cm trong không khí. Cho k=9.10-9 N. m2/C2 a xác định độ lớn lực điện giữa chúng
b. Khi đặt hệ vào môi trường điện môi có ( ectilon) 3=2 thì độ lớn lực điện là bao nhiêu?
c. Đặt hệ trong môi trường ko khí. Trên đường thẳng đi qua2 điện tích đặt điện tích q3=2nC vào giữa và cách q1 10 cm. Xác định lực điện tổng hợp lực tác dụng lên q1.

Athin plate moves between two parallel, horizontal, stationary flat surfaces at a constant velocity of v = 7.5 m/s. the two stationary surfaces are spaced 4 cm apart, and the medium between them is filled with oil whose viscosity is 0.9 n·s/m2. the part of the plate immersed in oil at any given time is 2 m long and 0.5 m wide. if the plate moves through the mid-plane between the surfaces, determine the force required to maintain this motion. what would your response be if the plate was 1 cm from the bottom surface (h2) and 3 cm from the top surface (h1)? if the plate moves through the mid-plane between the surfaces, the force required to maintain the motion will be n. if the plate was 1 cm from the bottom surface (h2) and 3 cm from the top (h1) surface, the force required to maintain the motion would be n.

Why should seat belts not be mandatory quick plz

You throw a small rock straight up from the edge of a highway bridge that crosses a river. the rock passes you on its way down, 7.00 s after it was thrown. what is the speed of the rock just before it reaches the water 28.0 m below the point where the rock left your hand? ignore air resistance.