Answer:
C. Luster
Explanation:
Luster is a phenomenon which refers to the manner with which the outer surface of a mineral reflects light.
Depending on the mineral, the 'luster' can differ. For example, in some minerals, the surface appears to be translucent, while in others, the surface appears to be transparent.
There are different types of luster, but they are categorized majorly into two:
- Metallic luster (the surface of the mineral appears like the surface of a metal).
- Non metallic luster.
Earth distance to the Sun is about 40 times the Moon's distance from earth.
<u>Explanation:</u>
- The Earth's distance from the Sun is about 93 million miles. When it expressed in Km, it is 150 million Km.
- The Moon's distance from Earth is 238,855 miles. When it is 40 times then it will approximately equal to 93 million miles.
- The Sun's distance from Venus is 67.237 million miles. The Sun's distance from mercury is 35.832 million miles.
Answer:
Explanation:
Given
length of string 
frequency 
time taken by wave to reach at other end 
speed of wave is given by



wavelength of is given by


Answer and explanation;
In 1670 Gabriel Mouton, Vicar of St. Paul’s Church and an astronomer proposed the swing length of a pendulum with a frequency of one beat per second as the unit of length.
In 1791 the Commission of the French Academy of Sciences proposed the name meter to the unit of length. It would equal one tens-millionth of the distance from the North Pole to the equator along the meridian through Paris.It is realistically represented by the distance between two marks on an iron bar kept in Paris.
In 1889 the 1st General Conference on Weights and Measures define the meter as the distance between two lines on a standard bar that made of an alloy of 90%platinum with 10%iridium.
In 1960 the meter was redefined as 1650763.73 wavelengths of orange-red light, in a vacuum, produced by burning the element krypton (Kr-86).
In 1984 the Geneva Conference on Weights and Measures has defined the meter as the distance light travels, in a vacuum, in 1299792458⁄ seconds with time measured by a cesium-133 atomic clock which emits pulses of radiation at very rapid, regular intervals.
P=I*E
Power (P)
Voltage (E)
Amps (I)