I think the correct answer would be that because electromagnets are powerful and can be turned off and on anytime. Electromagnet is a magnet in which the magnetic field is made by the electric current that is induced to the system.
If the soloist produces "x" decibels and the 10-person choir produces "y" decibels, combined they will produce "x+y" decibels.
The second choir has 90 additional singers, we base our description on the first choir. If a 10-person choir produces "x+y" decibels, then the 90 person choir produces 10 (x+y) decibels.
Heat engines are less than 100% efficient because absolute zero cannot be reached
Rhythmic gymnastics, trampoline gymnastics, javelin, diving, volleyball, and more due to the lack of gravity on the moon.
