Answer:
The lens to be used for the objective is lens A
Explanation:
The objective of a compound microscope
The focal length of the lens used for the objective = 1/(magnification obtained)
The focal length of most modern is equal to the tube length
The range of sizes for the focal length of a microscope is between 2 mm and 40 mm
Therefore, the appropriate lens to be used for the objective of the compound is lens A that has a focal length of 0.50 cm = 5 mm
"The wavelengths are getting longer, meaning the star is moving away from the observer" is the one among the following choices given in the question that this means about the length of light waves and movement of the star. The correct option among all the options that are given in the question is the fourth option or option "D".
Answer: Nitrogen
Explanation: Nitrogen makes up 78% of the atmosphere, Oxygen makes up 21%, and Argon 0.9%.
Water vaper makes up between 1-4%, depending on the region.
Carbon Dioxide makes up only about 0.04%.
Since we are only looking at the vertical height, we can use the free fall equation to find the height:
h = 0.5*g*t^2, where h is height in m, g is acceleration due to gravity (9.81 m/s^2), and t is time in seconds
h = 0.5*(9.81 m/s^2)*(3.7 s)^2
h = 67.15 m
Therefore, the 7th floor window is 67.15 m above ground level.
