That waves travel faster than the wave lenght!
Here we can use coulomb's law to find the force between two charges
As per coulombs law
]tex]F = \frac{kq_1q_2}{r^2}[/tex]
here we have




now by using the above equation we have


so here the force between two charges is of above magnitude and this will be repulsive force between them as both charges are of same sign.
Answer: B
Explanation:
An unbalanced force (net force) acting on an object changes its speed and/or direction of motion. An unbalanced force is an unopposed force that causes a change in motion.