What do you call a large number of photons moving together in the same direction

Which would not reduce the amount of green house gasses in the air

(01.02 mc) nicole pushes her bike up a hill. overhead, the sun exerts a gravitational force on earth. which statement is true about the bike and earth? they both experience contact forces. they both experience non-contact forces. the bike experiences a non-contact force and earth experiences a contact force. the bike experiences a contact force and earth experiences a non-contact force. they both experience non-contact forces.

The solid that is formed and usually sinks to the bottom of a solution is the