The area of the circle with radius r is
A = πr²
The rate of change of area with respect to time is

The rate of change of the radius is given as

Therefore

When r = 10 ft, obtain

Answer: - 40π ft²/s (or - 127.5 ft²/s)
Answer:
It changes at a rate of 4/3 meter per second
Explanation:
In the given figure below we have
Solving for Y given
we get

Answer:
C) Unscrew one light. If the other lights turn off, it's a series circuit.
Explanation:
THIS IS THE COMPLETE QUESTION BELOW;
A strand of 10 lights is plugged into an outlet. How can you determine if the lights are connected in series or parallel? A) Unscrew one light. If the other lights stay on, it's a series circuit. B) Unplug the strand. If the first light stays on, it's a series circuit. C) Unscrew one light. If the other lights turn off, it's a series circuit. D) Cut the strand in half. If the plugged in half stays on, it's a series circuit.
SERIES CIRCUIT
In this circuit, the components there are in the same path, the entire circuit has the same current, each of the components posses different voltage drop. Hence, failure of one components to work, there will be break in entire circuit then other components cease to work.
PARALLEL CIRCUIT
This circuit has equal voltage drop across all the components, any problem in a component will not has effect on other components.
Therefore, if one want to determine if a light connection is in series or in parallel, one of the light can be unplugged if others stop working it means it's series, if other works it's parallel.
If the battery is reversed and reconnected to the bulb, the bulb will glow <span>with the same brightness. The correct option among all the options that are given in the question is the third option or the penultimate option. I hope that this is the answer that you were looking for and it has actually come to your help.</span>
Resistors and reactors, for use over 600 volts, shall not be installed in close enough proximity to combustible materials to constitute a fire hazard and shall have a clearance of not less than<u> 300 mm </u>from combustible materials.
Explanation:
- The hazards associated with high power industrial resistors are primarily due to their open construction, which is necessary for cooling.
- The exposed conductors which make up the resistors can be not only a shock hazard but also a thermal burn hazard.
- When a resistor fails, it either goes open or the resistance increases. When the resistance increases, it can burn the board, or burn itself up.
- Avoid touching non-flammable resistors in operation; the surface temperature ranges from approximately 350 °C to 400°C when utilized at the full rated value. Maintaining a surface temperature of 200°C or less will extend resistors service life.
- Do not apply power to a circuit while measuring resistance. When you are finished using an ohmmeter, switch it to the OFF position if one is provided and remove the leads from the meter.
- Always adjust the ohmmeter for 0 (or in shunt ohmmeter) after you change ranges before making the resistance measurement.