The following equation is Coulomb's law that describes the relationship between force,
charge and distance in medium of air:
where:
F= electric force, N
k Coulomb constant
q=charge on object, C
d = distance between charges, m
$F = \frac{kq_1q_2}{d^2}$
a) Determine the units of the constant k.
(3 marks)
b) Two balloons are charged with an identical quantity and type of charge: -6.25 nC. They
are held apart at a separation distance of 61.7 cm. Calculate the electric force of this
balloons. ($k = 8.99 \times 10^9 \text{ N} \cdot \text{m}^2/\text{C}^2$)
(3 marks)
c) Derive a new equation for F in lb, q in nC, d in inch.
(8 marks)