The efficiency of the steam engine is 78.9% because the rest of the work input is used to overcome friction.
<h3>What is efficiency of machines?</h3>
Efficiency of a machine expresses the useful work done by a a machine as a percentage.
- Efficiency of a machine = work output/work input × 100 %%
The efficiency of machines are always less than 100% percent due to energy losses due to friction and heat.
For the steam engine:
Work output = 225 J
Work input = 285 J
Efficiency = 225/285 × 100% = 78.9 %
Therefore, the efficiency of the steam engine is 78.9% because the rest of the work input is used to overcome friction.
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Can you show the diagram please
The answer to your quesiton is,
A) Venus has phases.
-Mabel <3
Work done by the force = Force x displacement. Power = work done/time = F.s/t = F.u.t/t = F.u = 95 x 20 = 1900J. {S=ut because acceleration is zero since car is moving at constant velocity}.
Answer:
7.98 m
Explanation:
In the given question,
distance above surface= 2 m
Distance penny from person = 8 m
Since the swimming pool is filled with water and atmosphere has air therefore the refractive index phenomenon will occur.
The refractive index of water: air is 4/3 (1.33).
Using the formula, 4/3 = real depth, apparent depth
real depth= 4/3 x apparent depth
Now, calculating apparent depth = 8 - 2
= 6 m
therefore, real depth = 4/3 x apparent depth
= 1.33 x 6
= 7.98
thus, 7.98 m is the real depth of water.