What type of system is best used to observe conservation of mass because all of the mass stays in one place? a balanced system
a sideways system
a closed system
an open system

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

Mike walks 100 meter north, then walks 30 meters south. after this, he walks another 10 meters north. what is the magnitude of his total displacement during this walk,in meters?

An electric current is flowing through the cord below.what will happen to this current if a magnet is brought near the cord? a. the electric current will stop flowing. b. it will exert a force on the voltage. c. the resistance of the wire will decrease. d. it will exert a force on the electric current.