Answer:
option B
Explanation:
given,
heating tap water from 16° C to 50° C
at the average rate of 0.2 kg/min
the COP of this heat pump is 2.8
power output = ?
the required power input is 0.169 kW or 0.17 kW
hence, the correct answer is option B
What can your employer do to protect you from overhead power lines?
1 answer:
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Answer:
153.2 J
Explanation:
Let's first list our given parameters;
mass (m) of the block = 10 kg
which slides down ( i.e displacement) = 2 m
kinetic coefficient of friction (μk) = 0.2
In the diagram shown below; if we take an integral look at the component of force in the direction of the displacement; we have
Fcos 40°
100 (cos 40°)
76.60 N
Workdone by the friction force can now be determined as:
W = × displacement
W = 76.60 × 2
W = 153.2 J
∴ the work done by the friction force = 153.2 J
Answer:
new boiler total cost = $229706.825
new boiler total cost = $127512
Explanation:
given data
power p1 = 80 kW
cost C = $160000
cost index CI 1 = 187
cost index CI 2= 194
cost capacity factor f = 0.6
power p2 = 120 kW
current cost = $18000
to find out
total cost and cost of 40 kW
solution
we consider here CN cost for new boiler and CO cost for old boiler
and x is capacity of new boiler
first we find old boiler current cost that is
current cost CO = C × .............1
put here value
current cost = 160000 ×
new current cost = $165989.304
and
use here power sizing technique for 124 kW
CN/CO = ...............2
put here value and find CN
CN/CO =
CN / 165989.304 =
CN = 211706.825
so new cost = $211706.825
so
total cost for new boiler is
total cost = new cost + current cost
total cost = 211706.825 + 18000
new boiler total cost = $229706.825
and
for 40 kW new cost will be
use equation 2
CN/CO =
CN / 165989.304 =
CN = 109512
so new cost is $109512
so
total cost for new boiler is
total cost = new cost + current cost
total cost = 109512 + 18000
new boiler total cost = $127512
Answer:
Temperature at center of apples = 11.2⁰C
Temperature at surface of apples = 2.7⁰C
Amount of Heat transferred = 17.2kJ
Explanation:
The properties of apple are given as:
k = 0.418 W/m.°C
ρ = 840 kg/m³
Cр = 3.81 kJ/kg.°C
α = 1.3*10 ⁻⁷ m²/s
h = 8 W/m².°C
d = 0.09m
r = 0.045m
t = 1 hour = 3600s
<h2>Solution</h2>Biot number is given as:
The constants λ₁ and A₁ corresponding to Biot number (from the table) are:
λ₁ = 1.476
A₁ = 1.239
Fourier Number is:
As Fourier Number > 0.2 , one term approximates solutions are applicable
The temperature at the center of apples, The temperature at surface of apples and Amount of heat transfer is found in the ATTACHMENT.
