Answer:
a) 0.78 s
b) 58.86m/s'
c) Galileo's law of free fall
Explanation:
a) 
b)At the bottom:
kinetic energy = potential energy
downwards
c) Galileo's law of free fall says regardless of the masses, bodies in a vacuum will fall, on the earth, at the same acceleration
Is there a certain context to this question so that I can answer it better?
In order to answer this question, I realized that I needed to know the index
of refraction for ruby, so I went and looked it up. It's 1.762 to 1.770 .
I started trying to remember how to use this number and the critical angle
to find the index of refraction of the other medium. That's when I saw the
absurd unit "degrees celsius" for the critical angle, and I got discouraged.
But I perked up very quickly, when I realized that I'm still on the "index of
refraction" list, and while I'm there, I might as well just go ahead and
look up ethyl alcohol too.
It's 1.36 .
1. What is the force of the marble?
For an object near the surface of the earth, the gravitational force acting upon the object is given by:
F = mg
F is the gravitational force, m is the object's mass, and g is the acceleration of objects due to earth's gravity.
Given values:
m = 0.025kg, g = 9.8m/s²
Plug in the given values and solve for F:
F = 0.025×9.8
F = 0.25N
2. What is the marble's potential energy at the start of its fall?
The gravitational potential energy of an object near the earth's surface is given by:
PE = mgh
PE is the potential energy, m is the object's mass, g is the acceleration of objects due to earth's gravity, and h is the object's relative height.
new given values:
h = 0.08m
Since F = mg, you can simply multiply F×h to get PE. Use the result from question 1:
PE = F×h
PE = 0.25×0.08
PE = 0.02J
it is actually natural resources