C. Observations and measurements
The correct option is <u>D</u>.
Qualitative observations are observations that are made using our senses of sight, hearing, smell, taste and feel. These observations do not involve numbers or measurements of any kind.
The student's observations regarding the squirrel as is mentioned in options A, B and C involve measurements. Therefore these are not qualitative observations.
Option D, however, is made on the basis of sight, where the student observes the squirrel moving in a zigzag manner.
Therefore, of all the three observations, the student's observation that the squirrel ran in a zigzag pattern is the qualitative observation.
Light. The black hole is a vacuum, and not even light can escape it's suction
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
<u>Answer</u>
3.2857 g/cm³
<u>Explanation</u>
Density of a material is the mass of a unit volume of that material. It's SI unit is Kg/m³ but its has other units like g/cm³.
Density = mass/volume
= 46/14
= 3.2857 g/cm³
