They are attractive
They don’t depend on charge
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:
The length of the stick is 0.28 m.
The time the stick take to move is 0.97 ns.
Explanation:
Given that,
Relative speed of stick v= 0.96 c
Speed of light 
Proper length of stick = 1 m
We need to calculate the length of the stick
Using formula of length

Put the value into the formula



We need to calculate the time the stick take to move
Using formula of time

Put the value into the formula



Hence, The length of the stick is 0.28 m.
The time the stick take to move is 0.97 ns.
Answer: 65.25 J
Explanation:
Kinetic Energy K.E. = 1/2 * m * v^2 ; where m is the mass of the body and v is the velocity of the body ; K.E. = 1/2 * 0.145 * 30 * 30 = 65.25 Joules