Some buildings have electromagnets to hold fire doors open when the building is
occupied. These magnets are mounted to the wall, like a doorstop, behind the door.
Thinking about the actions a fire alarm system would need to perform to control a fire,
what is the advantage of using a system like this to hold the doors? How might a system
like this be an advantage, or a disadvantage, in the event of a natural disaster?
Answers: 3
Physics, 21.06.2019 21:00
An electric current in a wire will push or pull on a permanent magnet. which statement best explains how an electric current creates an electromagnetic force on another magnet?
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The law of the conservation of momentum says that the total momentum of any closed and isolated system cannot
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The electric potential a distance r from a small charge is proportional to what power of the distance from the charge? a. r^-1 b. r c. r^-2 d. r^2
Answers: 1
Physics, 22.06.2019 18:30
Adolphin emits ultrasound at 100khz and uses the timing of reflections to determine the position of objects in the water. part a what is the wavelength of this ultrasound? assume that temperature of water is 20 degrees c. answer in cm
Answers: 2
Some buildings have electromagnets to hold fire doors open when the building is
occupied. These mag...
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