I searched for you and i think its Velocity. it would be nice if u put the answer choices though
If one bulb goes out then all the others won't light up because electricity will be cut off. It's a disadvantage because in a parallel circuit if one bulb burns out all the others will still be on because they won't be affected. I hope I've helped you ☺
1. Frequency: 
The frequency of a light wave is given by:

where
is the speed of light
is the wavelength of the wave
In this problem, we have light with wavelength

Substituting into the equation, we find the frequency:

2. Period: 
The period of a wave is equal to the reciprocal of the frequency:

The frequency of this light wave is
(found in the previous exercise), so the period is:

Answer:
A. Kinetic energy is converted to electric potential energy, and the proton moves more slowly.
Explanation:
When a moving proton is brought close to a stationary one, the kinetic energy of the moving one is converted to electric potential and the proton moves more slowly.
Kinetic energy is the energy due to the motion of a body. A moving proton will possess this form of energy.
Two protons according to coulombs law will repel each other with an electrostatic force because they both have similar charges. This will increase their electric potential energy of both of them.
Potential energy is the energy at rest of a body. As it increases, the motion of a body will be slower and it will tend towards being stationary.
1) 0N... friction opposes the motion of an object, since the block is at rest there is no motion thus no friction
2) F=ma
= (5.5kg)(30m/s)
=165 N