Answer:
Wavelength is calculated as 213.9 nm
Solution:
As per the question:
Wavelength of light = 570 nm
Time, t = 16.5 ns
Thickness of glass slab, d = 0.865 ns
Time taken to travel from laser to the photocell, t' = 21.3
Speed of light in vacuum, c = 
Now,
To calculate the wavelength of light inside the glass:
After the insertion of the glass slab into the beam, the extra time taken by light to cover a thickness t = 0.865 m is:
t' - t = 21.3 - 16.5 = 4.8 ns
Thus


where
n = refractive index of the medium
v = speed of light in medium


n = 2.66
Now,
The wavelength in the glass:


Answer:
Ball hit the tall building 50 m away below 10.20 m its original level
Explanation:
Horizontal speed = 20 cos40 = 15.32 m/s
Horizontal displacement = 50 m
Horizontal acceleration = 0 m/s²
Substituting in s = ut + 0.5at²
50 = 15.32 t + 0.5 x 0 x t²
t = 3.26 s
Now we need to find how much vertical distance ball travels in 3.26 s.
Initial vertical speed = 20 sin40 = 12.86 m/s
Time = 3.26 s
Vertical acceleration = -9.81 m/s²
Substituting in s = ut + 0.5at²
s = 12.86 x 3.26 + 0.5 x -9.81 x 3.26²
s = -10.20 m
So ball hit the tall building 50 m away below 10.20 m its original level
a. Particles in warmer objects make particles in colder objects move faster.
A motion where gravity is the only force acting upon it