Tại 2 điểm A và B cách nhau trong không khí có đặt 2 điện tích q1 = q2 = 16.108 C. Xác định cường độ điện trường do hai điện tích gây ra : a) M với MA = MB = 5 cm
b) N với NA = 5 cm , NB = 15 cm
c) C biết AC = BC = 8cm

Astone dropped into a well is heard to strike the water after 8seconds. find the depth of the well if the velocity of sound is 350m/s

Awater-filled u-tube manometer is used to measure the pressure inside a tank that contains air. the water level in the u-tube on the side that connects to the tank is 5 ft above the base of the tank. the water level in the other side of the u-tube (which is open to the atmosphere) is 2 ft above the base. determine the pressure within the tank.

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.