What do active solar heat systems have that passive systems do not have?.

The mantle is made up of which structural zones?

Acoil suspended freely, points in some direction when no current is passed through it . can you tell what will happen when a current is passed though it?

Which statement is true? a) the work done to lift an object 6 meters is greater than the gravitational potential energy it gains. b) the work required to push an object is less than the work required to pull an object the same distance. c) the work required to raise an object to a height is equal to the gravitational potential energy the object gains. d) the work done against gravity to lift an object straight up is greater than the work required to roll it up a ramp.