Answer: C. Radio-controlled toy airplane
Explanation:
Just did the quiz
Answer:
this could be called an open system.
Answer:
It is actually the 1st, 4th, and 5th answer choices :)
Explanation:
The efficiency of a heat engine is given by the expression 
The efficiency of a heat engine is the ratio of the work done by the engine to the heat given as the input to the engine.

The heat engine absorbs Q h from the hot reservoir , performs a work <em>W</em> on the absorbed heat and rejects Qc to the cold reservoir.
Therefore, the work done is given by,

Thus the efficiency is given by, 
Answer:
Bank angle = 35.34o
Explanation:
Since the road is frictionless,
Tan (bank angle) = V^2/r*g
Where V = speed of the racing car in m/s, r = radius of the arc in metres and g = acceleration due to gravity in m/s^2
Tan ( bank angle) = 40^2/(230*9.81)
Tan (bank angle) = 0.7091
Bank angle = tan inverse (0.7091)
Bank angle = 35.34o