A balloon expanding would count as work because it is moving and none of the others are. However, I think that James pedaling also works because at least he is using his leg muscles even though he's not moving. He is working because he is exercising himself and that count as working. I would chose James over all of them.
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.
Learn more about efficiency of machines at: brainly.com/question/7536036
#SPJ1
Answer:
C .96 meters
Explanation: i just had this question
Velocity change v time because ACCELERATION=CHANGE IN VELOCITY/TIME
Answer:
5 miles per hour
Explanation:
if you divide 15 by 3 you get 5, therefore the student is going 5 miles per hour.
