Cho 3 điện tích q1 = 2.10-9 C; q2 = 3.10-9 C và q3 = -3.10-9C đặt lần lượt tại 3 đỉnh của một tam giác vuông tại A trong không khí. Cho AB = 3 cm; AC = 4 cm. Tính lực điện do q2 và q3 tác
dụng lên q1.

When using two-wire cable to feed a 240-v appliance that does not require a neutral wire, you should a. mark both ends of the white wire green. b. use the cable as is. c. use only the black wire. d. mark both ends and any exposed area of the white wire black.

Ascrew incorporates which other simple machine? lever wheel and axle inclined plane pulley

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.