Answer:
13 u2 = 0 – (2 × –2 m/s2 × 6 m) = 24, u = 4.9 m
Explanation:
Answer:
The answer is the top choice. (-1)
Explanation:
We are dealing with a negative number here, so we should start at negative five on the number line. From here we see that we are subtracting a negative number from it, which means we are really adding. (Review your rules for negative signs if this doesn't make sense.) So we add 4 to -5, and we get -1. Thus, we get the top choice.
Answer:
The correct option is;
(c) 64W
Explanation:
Here we have the Coefficient Of Performance, COP given by

The heat change from 23° to 6°C for a mass of 10 kg/h which is equivalent to 10/(60×60) kg/s or 2.78 g/s we have
= m·c·ΔT = 2.78 × 4.18 × (23 - 6) = 197.39 J
Therefore, plugging in the value for
in the COP equation we get;
which gives

Since we were working with mass flow rate then the power input is the same as the work done per second and the power input to the refrigerator = 63.674 J/s ≈ 64 W.
The power input to the refrigerator is approximately 64 W.
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