Hai điện tích q1 = 2. 10 – 9 C, q 2 = - 8.10 – 9C đặt tại hai điểm A, B trong chân không cách nhau một khoảng AB = 10 cm. Hãy xác định cường độ điện trường tại điểm a) C với CA = 2 cm, CB = 8 cm.
b) D với DA = 2 cm, DB = 12 cm.
c) M với MA = 6 cm, MB = 8 cnm.
d) N với NA = NB = 10 cm.

"an open tank has the shape of a right circular cone. the tank is 6 feet across the top and 5 feet high. how much work is done in emptying the tank by pumping the water over the top edge? note: the density of water is 62.4 lbs per cubic foot."

The earth is constantly spinning on its axis, like you might spin a basketball on your finger. it is this spinning of the earth that causes

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.