What is the name of the game mechanic in which the player "slides" towards obstacles?

You are looking for Frictionless Ice

Ice is not merely slippery; it's a physics-defying miracle lubricant that renders characters unable to make the slightest change in direction until the inevitable collision with an obstacle or wall, or in more malevolent circumstances, until the character is sent hurtling down a bottomless pit. So much as a single step of forward momentum is enough to send the character, puzzle block, or otherwise significant object sliding three screens in that direction. Of course, there is no diagonal.

This is actually developed from an old physics problem that goes with the study of Newton's law of motion (for each action there is an equal but opposite reaction).

The idea is that you would throw an object, which would cause you to receive the opposite and equal force to the throw, and move in a direction exactly opposite to my throw with just as much force as whatever was tossed.