First one is D and Second one is B
Answer with Explanation:
We are given that
Initial velocity,u=4.5 m/s
Time=t =0.5 s
Final velocity=v=0m/s
We have to find the deceleration and estimate the force exerted by wall on you.
We know that
Acceleration=
Using the formula
Acceleration=
deceleration=a=
We know that
Force =ma
Using the formula and suppose mass of my body=m=40 kg
The force exerted by wall on you
Force=
I think you would hear a lower pitch
Option (D) is correct that all of the above are physical properties of non metals.
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Answer:
1178 nm
Explanation:
We are given that
Wavelength of light=

We have to find the thickness of spacer if five dark fringes are observed between the edges of the glass.
Suppose that first dark fringe and fifth dark fringe near spacer, then the path length of light is 4 times the wavelength of light.
The light passes through air film is two times then the change in air film thickness from one edge to other is two times the wavelength of light.
Change in air film thickness from one edge to other edge is same as the thickness of spacer.
Therefore, thickness of spacer=
Thickness of spacer=
m
Thickness of spacer=1178 nm
Hence, the thickness of spacer=1178 nm