Question

if the air cushion is no longer there, do you think it is correct to say that the puck stops by itself? explain your ideas. what do you think would happen to the puck if, while it was gliding across the table, the pump was not shut off completely but only turned down a bit so that less air came out of the tiny holes in the tabletop? would it stop as quickly as it stopped when the air was turned off completely? explain your ideas.

Explanation:

When the air - cushion is removed, the puck stops due to friction. Friction is a force that opposes motion between two surfaces in contact. When the air - cushion is present, it reduces the friction between the puck and the table. If the pump is turned down but not off completely, less air comes out of the holes. This means there is still some air - cushion effect, so the friction is not as high as when the air is turned off completely. As a result, the puck will not stop as quickly.

Answer:

1. It is not correct to say the puck stops by itself when the air - cushion is removed. It stops due to friction between the puck and the table surface.
2. The puck will not stop as quickly when the pump is turned down a bit compared to when the air is turned off completely because there is still some air - cushion effect reducing the friction between the puck and the table.