Answer:
The minimum compression is 
Explanation:
From the question we are told that
The mass of the block is 
The spring constant is 
The coefficient of static friction is 
For the the block not slip it mean the sum of forces acting on the horizontal axis is equal to the forces acting on the vertical axis
Now the force acting on the vertical axis is the force due to gravity which is mathematically given as

And the force acting on the horizontal axis is force due to the spring which is mathematically represented as

where x is the minimum compression to keep the block from slipping
Now equating this two formulas and making x the subject

substituting values we have


Answer
Given,
refractive index of film, n = 1.6
refractive index of air, n' = 1
angle of incidence, i = 35°
angle of refraction, r = ?
Using Snell's law
n' sin i = n sin r
1 x sin 35° = 1.6 x sin r
r = 21°
Angle of refraction is equal to 21°.
Now,
distance at which refractive angle comes out
d = 2.5 mm
α be the angle with horizontal surface and incident ray.
α = 90°-21° = 69°
t be the thickness of the film.
So,


t = 2.26 mm
Hence, the thickness of the film is equal to 2.26 mm.
Answer:
chemical energy to electrical energy to sound energy to heat energy