A 5.5-kW resistance heater in a water heater runs for 3 hours to raise the water temperature to the desired level. Determine the
1 answer:
Answer:
16.5 kwh and 59400 kJ.
Explanation:
kWh is a measure of energy that is equivalent to the power in kw times the number of hours the device worked.
In this case, it would be equal to:
1 kw also means 1kj of energy spent per second. With this, we calculate the amount of energy in kJ spent by the resistance:
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Answer:
The resultant velocity of the helicopter is .
Explanation:
Physically speaking, the resulting velocity of the helicopter (), measured in meters per second, is equal to the absolute velocity of the wind (
), measured in meters per second, plus the velocity of the helicopter relative to wind (
), also call velocity at still air, measured in meters per second. That is:
(1)
In addition, vectors in rectangular form are defined by the following expression:
(2)
Where:
- Magnitude, measured in meters per second.
- Direction angle, measured in sexagesimal degrees.
Then, (1) is expanded by applying (2):
(3)
If we know that ,
,
and
, then the resulting velocity of the helicopter is:
The resultant velocity of the helicopter is .