Physics please check
posted by Mary on .
A charge of 3.00 µC is fixed at the center of a compass. Two additional charges are fixed on the circle of the compass (radius = 0.125 m). The charges on the circle are 4.60 µC at the position due north and +5.00 µC at the position due east. What is the magnitude and direction of the net electrostatic force acting on the charge at the center? Specify the direction relative to due east (0°).
Magnitude
_____N
Direction
______°
Magnitude:
(8.99e9)(4.6e6)(3.0e6)/ (0.125)^2
=7.94 N
(8.99e9)(5.0e6)(3.0e6)/ (0.125)^2
=8.63 N
Adding both values as vectors:
sqrt[(7.94N squared)+(8.63N squared)]
Magnitude= 11.73 N
Direction:
theta = inverse tan (7.94/8.63)
= 42.62 degrees South of East

LOOks good to me!