Answer:

Explanation:
The formula for the force exerted between two charges is

where k is the Coulomb constant.
The charges are identical, so we can write the formula as


Answer:

Explanation:
Impulse-Momentum relation:


We solve the equations in order to find the braking force:

Name the element and explain why it is unusual:
a)A liquid metal
b)A non-metal that conducts electricity
Answer: Photoelectric wave
Explanation: Because it represents an interaction between light and matter that describes light as an electromagnetic wave.