Can a box accelerate positively going down a frictionless incline?

[hager]

Homework Statement

Is it possible for a box going down on a frictionless incline plane to have not a negative acceleration but positive acceleration? Please help, it is confusing.

Homework Equations

The Attempt at a Solution

 

[berkeman]

Homework Statement

Is it possible for a box going down on a frictionless incline plane to have not a negative acceleration but positive acceleration? Please help, it is confusing.

Homework Equations

The Attempt at a Solution

Acceleration is a vector quantity. So the sign of the vector depends on how you choose your coordinate system. If an object is free-falling at the surface of the Earth, then the acceleration due to gravity "g" is positive if the Z axis points down, and negative if it points up. As long as you keep your coordinate system consistent, you could choose either way.