Coulomb, unit of electric charge in the metre-kilogram-second-ampere system, the basis of the SI system of physical units. ... The coulomb is defined as the quantity of electricity transported in one second by a current of one ampere.
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Answer:
The elastic potential energy of the spring change during this process is 21.6 J.
Explanation:
Given that,
Spring constant of the spring, 
It extends 6 cm away from its equilibrium position.
We need to find the elastic potential energy of the spring change during this process. The elastic potential energy of the spring is given by the formula as follows :

So, the elastic potential energy of the spring change during this process is 21.6 J.
Answer:
Explanation:
Use the one-dimensional equation
which says that the final velocity of an object is equal to the object's initial velocity plus its acceleration times time. We are looking for time. That means the equation looks like this:
0 = 30 + (-4)t and
-30 = -4t so
t = 7.5 sec
Answer:
B. Radio waves
Explanation:
Radio waves are transmitted easily through air. They do not cause damage if absorbed by the human body, and they can be reflected to change their direction. These properties make them ideal for communications.
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