Answer:
Explanation:
It is given that,
Height of the building, h = 245 ft
The base of the building and shadow is x.
Let is the angle of elevation that is formed by lines from the top and bottom of the building to the tip of the shadow. Using the trigonometric ratio as :
When x = 300 feet
So, the rate of change of the angle of elevation is -0.001633 rad/ft. Hence, this is the required solution.
Power dissipated by a resistor = (current)² x (resistance).
0.25 W = (0.02 A)² x (resistance)
This resistor = (0.25 W) / (0.02 A)²
This resistor = 625 ohms
If we want it to dissipate 0.5 W, then
0.5 W = (current)² x (625 ohms)
Current = √(0.5/625)
Current = √(0.0008)
<em>Current = 28.28 mA</em>
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A slightly easier way:
Since the power is = I²R, it grows in proportion to (current)² .
We want to double the power dissipated, so we only need to increase the current by the factor of √2 .
(20 mA) x (√2) = <em>28.28 mA </em>
Answer:
I think the correct answer is period