Cho q1= 8.10 mũ -8C ; q2 = -8.10 mũ -8C . Đặt tại 2 điểm A và B cách nhau 6cm trong không khí . Xác định lực điện dung dịch lên qo = 8.10 mũ -8C đặt tại : a. CA= 4cm , CB= 10cm b. CA=CB= 5cm c. CA= 6cm , CB= 6cm

The motor m applies a time-varying force of f (200 t) n, where t is in seconds. box b with mass 200 kg starts from rest, and the coefficients of kinetic and static friction are 0.2 and us 0.3 the acceleration due to gravity is g 9.8 m/s2 b 300 a) find the time ' when the box starts to move. b) calculate the speed of the crate at 3 s c) calculate the power delivered by the motor at t 3 s

An ideal polarizer with its transmission axis rotated 30 degrees to the vertical is placed in a beam of unpolarized light of intensity 10w/m^2. after passing through the polarizer, what is the intensity of the beam? a. 8.7 w/m^2 b. 7.5 w/m^2 c. 5.0 w/m^2 d. 10 w/m^2 e. 2.5 w/m^2

How does the kinetic energy of a charge change as the charge moves under the effect of an electric field from higher potential to lower potential? a.the kinetic energy increases.b.the kinetic energy decreases.c.the kinetic energy remains the same.d.the kinetic energy is always zero.