Work Energy And Power Question 291
Question: An engine is hauling a train of mass M kg on a level track at a constant speed v m/s. The resistance due to friction is $ fN/kg $ . What extra power must the engine develop to maintain the speed up a gradient of h in s :
Options:
A) $ \frac{mghv}{s} $
B) $ \frac{mghs}{v} $
C) $ Mghvs $
D) zero
Show Answer
Answer:
Correct Answer: A
Solution:
[a] Extra power, $ P = mg sin \theta \times v $
$ =Mg\times \frac{h}{s}\times v=\frac{Mghv}{s}. $
