Answer:
The minimum thickness = 83.92 nm
Explanation:
The relation between the wavelength in a particular medium and refractive index 
where ;
= wavelength of the light in vacuum
n = refractive index of medium with respect to vacuum
For one phase change :

Replacing 1.43 for n and 480 nm for λ; we have:

t = 83.92 nm
Thus; the minimum thickness = 83.92 nm
If the object is moving in a straight line at a constant speed, then that's
the definition of zero acceleration. It can only happen when the sum of
all forces (the 'net' force) on the object is zero.
And it doesn't matter what the object's mass is. That argument is true
for specks of dust, battleships, rocks, stars, rock-stars, planets, and
everything in between.
Answer:
Explanation:
4.95s≈5s
Use equation :
h=G*t²/2
h=120m ----hight of cliff
G=9.81m/s²
t=?
-----------------------
h=G*t²/2
120m=9.81m/s²*t²/2
240m=9.81m/s²*t²
t²=240m/ 9.81m/s²
t²=24.46s
t=√24.46s²
t=4.95 s≈5s
They can tell what type/species the dinosaur was