Two identical point masses of 4kg are separated by 0.50m. A point P lies on the line joining them, 0.10m from one of the masses and between the two masses. What is the magnitude of the net gravitational field at P?
a) 5.3×10−8N kg−1
b) 2.0×10−9N kg−1
c) 2.5×10−8N kg−1
d) 2.8×10−8N kg−1