Complete Question
The complete question is shown on the first uploaded image
Answer:
A

B

C
The correct option is B
Explanation:
From the question we are told that
The refractive index of water is 
The refractive index of ethanol is 
Generally the threshold velocity for creating Cherenkov light from a charged particle as it travels through water is mathematically evaluated as

Where c is the speed of light with value 


Generally the threshold velocity for creating Cherenkov light from a charged particle as it travels through water is mathematically evaluated as

=> 
=> 
c) 101kPa
Hope I helped! ( Smiles )
Answer:
Explanation:
Give that,
Spring constant (k)=40N/m
Force applied =75N
Since the force is applied to the right, we don't know if it is compressing or stretching the spring
So let assume it compress
Using hooke's law
F=-ke
e=-F/k
Then, e=-75/40
e=-1.875m
The deformation is 1.875m.
Let assume it stretch
Using hooke's law
-F=-ke
e=F/k
Then, e=75/40
e=1.875m
The elongation is 1.875m