When an exothermic reaction releases thermal energy, this energy is usually...
C. Harnessed to do work
(Not 100% on that)
Answer:
b) the refracted ray has an angle of 90 degrees
Explanation:
The angle of incidence is measured with respect to the normal separation of the media. The critical angle for total internal reflection occurs is:

Here
and
are the refractive index of the mediums. This equation is an application of Snell's law, for the case where the refracted ray has an angle of
.
Words less true are seldom if ever spoken.
Answer:
Part a)

Part b)

Part c)
distance L is independent of the mass of the sphere
Explanation:
Part a)
As we know that rotational kinetic energy of the sphere is given as

so we will have

so we will have




Part b)
By mechanical energy conservation law we know that
Work done against gravity = initial kinetic energy of the sphere
So we will have



Part c)
by equation of energy conservation we know that

so here we can see that distance L is independent of the mass of the sphere