(a) why do we call this system a self-pumping system? (b) suggest why the system needs a pump on cold nights.

Which accurately compares concave and convex lenses?

Need this now! do pilots live long

If two students are running down the hall toward each other, trying to get to class, and they have the same mass and acceleration, what will happen when they collide? will their forces cancel out or will each one experience a reaction?