Answer:
a) 
Explanation:
a) Let consider that heat pump is reversible, so that the Coefficient of Performance is:



The minimum heat received by the house must be equal to the heat lost to keep the average temperature constant. Hence:

The minimum power supplied to the heat pump is:



Efficiency is the minimum use of energy to accomplish the task. The wasted energy will be 375 J when 750 J of energy is given.
<h3>What is wasted energy?</h3>
Wasted energy is energy that is not useful when the transformation in the system occurs.
Total energy = 750 J
The efficiency of the system = 50 %
Output work (OW) is calculated as:
Efficiency = output work ÷ input work × 100%
750 × 50 = 100 OW
OW = 375 J
Wasted energy = Total energy - output work
= 750 - 375
= 375 J
Therefore, the machine is 50 % inefficient and has wasted energy of 375 J.
Learn more about wasted energy here:
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Solution :
Given :
External diameter of the hemispherical shell, D = 500 mm
Thickness, t = 20 mm
Internal diameter, d = D - 2t
= 500 - 2(20)
= 460 mm
So, internal radius, r = 230 mm
= 0.23 m
Density of molten metal, ρ = 
= 
The height of pouring cavity above parting surface is h = 300 mm
= 0.3 m
So, the metallostatic thrust on the upper mold at the end of casting is :

Area, A 




= 7043.42 N
Answer:

Explanation:
To solve this problem we use the expression for the temperature film

Then, we have to compute the Reynolds number

Re<5*10^{5}, hence, this case if about a laminar flow.
Then, we compute the Nusselt number

but we also now that

but the average heat transfer coefficient is h=2hx
h=2(8.48)=16.97W/m^{2}K
Finally we have that the heat transfer is

In this solution we took values for water properties of
v=16.96*10^{-6}m^{2}s
Pr=0.699
k=26.56*10^{-3}W/mK
A=1*0.5m^{2}
I hope this is useful for you
regards
Answer:
The speed of shaft is 1891.62 RPM.
Explanation:
given that
Amplitude A= 0.15 mm
Acceleration = 0.6 g
So
we can say that acceleration= 0.6 x 9.81

We know that

So now by putting the values



We know that
ω= 2πN/60
198.0=2πN/60
N=1891.62 RPM
So the speed of shaft is 1891.62 RPM.