It would help if there are some options, but some common sources:
Televisions
Microwave Ovens
Cell Phones
Satellites
Wired Computers
CD players
etc.
yes. youre using energy to make the wagon with the child in the wagon
The correct answer is
A) true
In fact, the electrical force can be present only if the two objects have a net charge different from zero, because the electrical force is proportional to the value of the charges:

so, if they are neutral they cannot exert an electrical force between each other, because their charge Q is zero.
Viceversa, the gravitational force is always present when the objects have masses, since the force is proportional to the value of the masses:

so, even if the two objetcs are neutral, if they have mass, they exert a gravitational force to each other.
Answer:
The compression ratio is 10
Explanation:
Given
--- swept volume
--- compression volume
Required
Determine the compression ratio (CR)
This is calculated as:




Since the current is inversely propotional to its resistance, when the voltage is doubled the current will be one-half