Explanation:
Formula for maximum efficiency of a Carnot refrigerator is as follows.
..... (1)
And, formula for maximum efficiency of Carnot refrigerator is as follows.
...... (2)
Now, equating both equations (1) and (2) as follows.
= 
= 
= 
= 2.5
Thus, we can conclude that the ratio of heat extracted by the refrigerator ("cooling load") to the heat delivered to the engine ("heating load") is 2.5.
The force is opposite to the displacement
Btu/(lb-°F) J/(g-°C i mean this is the correct answer
Answer:
21.7 seconds.
Explanation:
Woman's velocity relative to train (23 m/s - 22.4 m/s) = 0.6 m/s
Distance woman wants to travel = 13m
To find how long she will take to move 13m relative to the train, take the distance she wants to travel divided by her velocity relative to the train.
(13m)/(0.6 m/s) = 21.6667 seconds or 21.7 seconds.
Therefore, it will take the woman 21.7 seconds to move 13m.
The correct answer is the Type of batteries
Explanation:
In an experiment, it is normal the researcher modifies one variable, in this case, the number of batteries (independent variable), and this variable affects the variable tested, in this case, the brightness of the bulb (dependent variable).
However, other factors or variables should be constant to guarantee the results are reliable. In this context, one factor that the student should keep constant is the type of batteries he uses because this is not one of the main variables and therefore it is not expected he changes this on purpose or this is affected by other variables. Moreover, by making any change the experiment can be negatively affected. For example, batteries might differ in their power capacity this can affect the brightness of the bulbs.
