The magnitude of the electrical force acting between a +2.4 × 10–8 c charge and a +1.8 × 10–6 c charge that are separated by 0.008 m is n, rounded to the tenths place.

To answer this question, we will simply use Coulomb's which is stated as follows:
F = k*q1*q2 / r^2 where:
F is the magnitude of the force between the two charges
k is a constant = 9.00 * 10^9 N.m^2/C^2
q1 =  +2.4 × 10–8 C
q2 = +1.8 × 10–6 C
r is the distance between the two charges = 0.008 m

Substituting in the equation, we get:
F = (9*10^9)(2.4*10^-8)(1.8*10^-6) / (0.008)^2 = 6.075 which is approximately 6.1 Newtons

Kinetic energy = 1/2mv^2. since the mass is constant we can form a ratio of it's kinetic energy at 60 divided by that at 30 to see ke(60)/ke(30) = +(60^2)/30^2). this may be said to 300% increase.