Another physics problem!! help!! ?

Question

I've been trying to do this problem for about an hour and I've already gotten it wrong 14 times!! It states something and then has 5 statements that are either true or false! Please Help! [:

A puck is sliding on a horizontal frictionless surface.

Answer True or False. (More than one statement may be true.)

-The puck will slow down slightly because of the air.

-The puck will continue moving because of inertia.

-The puck will slow down and eventually stop because of its mass.

-The puck will slow down slightly because of gravity.

-The puck will slow down because of inertia.

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Answer 1

Air is a type of friction (the air molecules rubbing against the sides of the puck as it moves past them causes friction that slows the puck down.) Although the SURFACE is frictionless, the air isn't, so the puck would slow down.

The puck will continue moving because of its inertia -- this is true. Inertia is the force that keeps it moving.

This is false, the only reason it would slow down because of mass is if there was friction on the surface (the harder the mass pushes down against the surface, the more friction there is.) Because this is a frictionless surface, this can be discounted.

The answer to the next one is similar to the "mass" question, above. MASS * GRAVITY* FRICTIONAL COEFFICIENT = FRICTIONAL FORCE.

So gravity will not slow the puck down.

Inertia will keep it moving forward. This is false.

Answer 2

1) True - Because of air resistance

2) True

3) False - if there is no friction and no air resistance it could theoretically keep moving at a constant speed forever.

4) False - its traveling horizontally so gravity has no effect its horizontal velocity

5) False - Inertia keeps things moving when no external forces affect them, it doesn't slow things down

Answer 3

if there is no air resistance the puck will continue moving

but any air resistance will cause slowing down so slightly

gravity is not important here because the puck is moving on a horizontal surface that is frictionless