Answer:
The minimum angular speed 57.0 rad/s
Explanation:
In this exercise we must use the relationships between the angular and linear magnitudes, for the speeds we have
v = w r
As they give us that linear velocity is constant, we will calculate the angular velocity for the two radii, external and internal
r1 = 11.75 cm (1 m / 100cm) = 0.1175 m
w1 = v / r1
w1 = 6.70 / 0.1175
w1 = 57.0 rd / s
R2 = 4.50 cm = 0.0450 m
w2 = 6.70 / 0.0450
w2 = 148 rad / s
The minimum angular speed 57.0 rad / s
The answer is B. High Pitch Sound
Answer:
Explanation:
Given
Temperature of Hot reservoir 
Temperature of Cold reservoir 
Heat reservoir 
Work done 
heat Exhaust 


L.H.S=R.H.S
thus it follows first law



Cycle Efficiency

Carnot efficiency is less than cycle thus it violates second law
Answer:
12.5m/s
Explanation:
(Assuming the question was asking for the speed just before it hit the ground)
We can use the first key equation of accelerated motion
Vf^2 = Vi^2+2aΔd
Vf^2 = 0 + 2(9.8)(8) (plugged in values, initial velocity is 0 since the ball was at rest)
Vf^2 = 156.8
Vf = 12.5 (squared both sides)