Answer:
The claim is valid.
Explanation:
Let assume that heat pump is reversible. The coefficient of performance for the heat pump is:



The claim is valid as real heat pumps have lower coefficients of performance.
Answer:
YES
Explanation:
If we connect batteries in series then the output voltage is the sum of the individual voltage of each battery i.e if you connect three 12 volts batteries in series then their output voltage will be 12+12+12=36 volts, but the current rating of the batteries in series will be same of the individual battery rating in 'mah'.
But when we connect the batteries in parallel their voltage is not added but their current rating in mah is addition of their individual rating.
So, If you want 24 volts from three 12 volts battery then you can connect two of them in series and the other one in parallel with them this will give 24 volts and the current will be addition of the two series batteries and the third which is in parallel with them. You can use this configuration if current value is not a big factor.
Answer:
Mechanical resonance frequency is the frequency of a system to react sharply when the frequency of oscillation is equal to its resonant frequency (natural frequency).
The physical dimension of the silicon is 10kg
Explanation:
Using the formular, Force, F = 1/2π√k/m
At resonance, spring constant, k = mw² ( where w = 2πf), when spring constant, k = centripetal force ( F = mw²r).
Hence, F = 1/2π√mw²/m = f ( f = frequency)
∴ f = F = mg, taking g = 9.8 m/s²
100 Hz = 9.8 m/s² X m
m = 100/9.8 = 10.2kg
Answer:
28.6 kg
Explanation:
The final weight can be calculated from the mixing data and formulae which is given as follows:
cement content = 
Computing the parameters and checking the tables gives 28.6 kg.