Answer:
a) 42.52°
b) 63.98°
Explanation:
Refractive index of pipe = 1.48 = n₂
Refractive index of air = 1.0003 = n₁

∴ Minimum angle of incidence is 42.52°
Refractive index of water = 1.33 = n₁

∴ Minimum angle of incidence is 63.98°
By definition, centripetal acceleration is given by:

Where,
v: tangential disk speed
r: disk radius
Substituting values in the given equation we have:

Rounding the result we have:

Answer:
The centripetal acceleration of the disc edge in m/s^2 is:

I would say that it is Meteors, Meteorites, and comets. (METEORS may be wrong)
I assume here that the engine operates following a Carnot cycle, which achieves the maximum possible efficiency.
Under this assumption, the efficiency of the engine (so, the efficiency of the Carnot cycle) is given by

where

is the cold temperature

is the hot temperature
For the engine in our problem, the cold temperature is 313 K while the hot temperature is 425 K, so the effiency of the engine is