The number of lines per mm in the diffraction grating is 326.
<h3>What is diffraction grating?</h3>
A diffraction grating is a type of optical instrument obtained with a continuous pattern. The pattern of the diffracted light by a grating depends on the structure and number of elements present.
The given data in the problem is
is the angle formed between the path of the incident light and the diffracted light = 9. 2°
λ is the wavelength of the light=490nm=4.9
N is the number of lines per mm in the diffraction grating=?
n is ordered = 1
The formula for the diffraction grating is;

The number of lines per mm is found as;

Hence the number of lines per mm in the diffraction grating is 326.
To learn more about diffraction grating refer to the link;
brainly.com/question/1812927
Answer:
Mar's orbital path is more than that of Earth, thus it takes more number of days to orbit around the sun.
Explanation:
Mars takes over 500 days to orbit all the way around the sun than Earth because its distance from the sun (228 million kilometers) is greater than that of Earth (150 million kilometers) which takes it 365 days.
Planets that orbit closer to the sun take shorter time to orbit around the sun because the cover a shorter orbital distance and orbit faster than those planets further from the sun.
<u>For example</u>
Using Earth's distance from the sun, 150 million kilometers and the number of days taken to orbits the sun ,365 days and the distance Mars is from the Earth, 228 million kilometers, you can approximate the time Mar takes to orbit the sun as:
Earth 150 million kilometers = 365 days
Mars 228 million kilometers= ?
Cross product ; (228 *365) /150 =555 -----(a value closer to that in the question)
Answer: (d)
Explanation:
Given
Mass of object 
Speed of object 
Mass of object at rest 
Suppose after collision, speed is v
conserving momentum

Initial kinetic energy

Final kinetic energy

So, it is clear there is decrease in kinetic energy . Thus, energy decreases and velocity becomes 2 m/s.
The answer is mass. I have to comment more than 20 characters.
C.) a magnetic field is the correct answer…