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?

Which of these statements is true? a. quarks pair with leptons to form protons and neutrons. b. quarks pair with bosons to form photons. c. quarks pair with photons to form protons and neutrons. d. quarks pair with other quarks to form protons and neutrons. e. quarks pair with electrons to form protons.

Your science teacher brings in a speaker to talk to your class about climate change. during the session, students ask a few questions. which questions are related to the current evidence on climate change

The magnitude of the magnetic field at a certain distance from a long, straight conductor is represented by b. what is the magnitude of the magnetic field at twice the distance from the conductor? a. at twice the distance, the magnitude of the field is 4b.b. at twice the distance, the magnitude of the field is 2b.c. at twice the distance, the magnitude of the field is b/2.d. at twice the distance, the magnitude of the field is b/4.e. at twice the distance, the magnitude of the field remains equal to b.