Answer:
The warming causes the oceans to release CO2. The CO2 amplifies the warming and mixes through the atmosphere, spreading warming throughout the planet. So CO2 causes warming AND rising temperature causes CO2 rise. Overall, about 90% of the global warming occurs after the CO2 increase.
Explanation:
Answer:
diameter is 14 mm
Explanation:
given data
power = 15 kW
rotation N = 1750 rpm
factor of safety = 3
to find out
minimum diameter
solution
we will apply here power formula to find T that is
power = 2π×N×T / 60 .................1
put here value
15 ×
= 2π×1750×T / 60
so
T = 81.84 Nm
and
torsion = T / Z ..........2
here Z is section modulus i.e = πd³/ 16
so from equation 2
torsion = 81.84 / πd³/ 16
so torsion = 416.75 / / d³ .................3
so from shear stress theory
torsion = σy / factor of safety
so here σy = 530 for 1020 steel
so
torsion = σy / factor of safety
416.75 / d³ = 530 × 
/ 3
so d = 0.0133 m
so diameter is 14 mm
Answer:
a) 8kW
b) $128
Explanation:
Given the coefficient of performance of the heat pump cycle to be 2.5
Energy delivered by the heat pump = 20kW
a) net power required to operate the heat pump = Energy delivered / coefficient of performance
Net power required = 20/2.5
= 8kW
b) Given the cost of electricity is $0.08 for 1kWhour
Since net power required to operate heat pump = 8kW
If the heat pump operate for 200hours, total power required for a month = 8kW×200hours = 1600kWhour
since 1kWh of electricity costs $0.08, cost of electricity used in a month when the pump operates for 200hour will be 1600kWh×$0.08 which is equivalent to $128
The following is a feedback mechanism for a system :
<u>The progress bar when downloading a file on iTunes</u>
<u></u>
Explanation:
- A feedback mechanism is a loop system wherein the system responds to a perturbation. The response may be in the same direction (as in positive feedback) or in the opposite direction (as in negative feedback).
- Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to feed back into itself.
- Evaluation feedback needs to be done “in the moment” to help the person receiving the feedback know where they stand.
- A feedback control system consists of five basic components: (1) input, (2) process being controlled, (3) output, (4) sensing elements, and (5) controller and actuating devices.
- Because negative feedback produces stable circuit responses, improves stability and increases the operating bandwidth of a given system, the majority of all control and feedback systems is degenerative reducing the effects of the gain.
