Answer:
Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work).
Explanation:
It is a measure of how well a machine reduces friction.
Answer:
The time taken by missile's clock is 
Solution:
As per the question:
Speed of the missile, 
Now,
If 'T' be the time of the frame at rest then the dilated time as per the question is given as:
T' = T + 1
Now, using the time dilation eqn:




(1)
Using binomial theorem in the above eqn:
We know that:

Thus eqn (1) becomes:


Now, putting appropriate values in the above eqn:


Answer:
The temperature of cold reservoir should be 246.818 K for efficiency of 35%
Explanation:
In first case we have given efficiency of Carnot engine = 26 % = 0.26
Temperature of cold reservoir 
We know that efficiency of Carnot engine is given by



For second Carnot engine efficiency is given as 35% = 0.35
And temperature of hot reservoir is same so 
So 

So the temperature of cold reservoir should be 246.818 K for efficiency of 35%
Comparative investigation is a research method that makes comparison across different countries of the world. Limitation : data set in different countries may be defined differently. Benefit : the method is flexible.
Answer:
the heavier skater has less momentum
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