The density of the object is approximately 1.91 kg per m³.
42 kg is a measure of mass, and 22 m³ is a measure of volume. Knowing this, you can use the relationship

to solve for the object's density.
42 kg

22 m³

1.91 kg per m³.
Answer: A medium is any substance or region through which a wave is transmitted. The speed of a wave is dependant on four factors: wavelength, frequency, medium, and temperature. Wave speed is calculated by multiplying the wavelength times the frequency (speed = l * f).
Remember, Your electric field lines drawn from positive charge (protons) and goes to negative charge (electron)
So, Your Answers would be:
15) B) Positive
16) A) Negative
17) B) Positive
18) A) Negative
19) B) Positive
20) B) Positive
Hope this helps!
Answer:
c. A Generator
Explanation:
The whole point of a generator is to produce electrical energy. The generator will use a mechanical motor usually running off of gas to produce electricity.