Answer:

Explanation:
<u>Average Speed
</u>
If an object travels a distance d in a time t regardless of the direction, the average speed is the quotient of the distance over the time:

It's known a person runs d=15 kilometers in t=2 hours, thus his/her average speed is:

Calculating:

Answer:
B) protons and neutrons.
Explanation:
The protons and neutrons are located in the nucleus of the atom and represent most of the 'mass' of the atom, that's their count that determine the 'mass' of an atom (like 12 for Carbon).
The electrons rotate around the nucleus and have a negligible mass.
The wavelength in nanometers of light when the energy is 1. 91 × 10^6 j for a mole of photons is <u>62. 8 nm.</u>
Wavelength is the distance among the same points (adjacent crests) within the adjoining cycles of a waveform signal propagated in space or along a cord. In wi-fi structures, this period is typically specified in meters (m), centimeters (cm), or millimeters (mm).
The wavelength is the distance between wave crests, and it is going to be the same for troughs. The frequency is the variety of vibrations that skip over a given spot in one 2nd, and it's far measured in cycles consistent with the second (Hz) (Hertz).
Frequency is the ratio of pace and wavelength in relation to speed. In comparison, wavelength refers to the ratio of pace and frequency. Audible sound waves are characterized by way of a frequency range of 20 to 20 kHz. In contrast, the variety of wavelengths of visible light is from four hundred to seven hundred nm.
<u>calculation:-</u>
*E=hc/λ
1.91 × 10^6 J = (6.62610⁻³⁴) (3.00*10⁸) / λ
λ= (6.62610⁻³⁴) (3.00*10⁸) / 1.91 × 10⁶ J
λ= 1.0410⁻³¹× 10⁻⁹ × 6.022*10²³
=<u> 62. 8 nm </u>
Learn more about wavelength here:-brainly.com/question/10728818
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The resistance of a conductor is given by

where L is the length of the wire,

the resistivity of the material and A the cross-sectional area.
We can see that if all the other quantities do not change, if the new length of the conductor is 4 times the original length:

, then the new resistance is also 4 times the original value: