# Question on a ramp

1. Jan 31, 2006

### SS2006

I have a 1kg weight on a rmap inclined 20degrees being pulled upwards and to the left
*******-
***********-
************** -
******************-
in that motion above(look at dashes only), is it -ma or +ma?
so the equation is

-a = t - mgsin20
or
a = t - mgsin20
im just wondering if a leeft movement has anythign to do with gravity (A) being + or-
thanks

Last edited: Jan 31, 2006
2. Jan 31, 2006

### Valhalla

try looking at it in terms of the forces acting in the X direction and the forces acting in the Y direction. Consider where you place your origin.

Then think about which vectors will be positive and which will be negative.

3. Jan 31, 2006

### SS2006

no no i just want a simple anaswre
i just meant weather acceleration should be -ma or +ma

4. Jan 31, 2006

### Cyrus

It has to do with how you define coordinate system.

5. Jan 31, 2006

### SS2006

i have an exam tomorrow and i just wanted to know , are you saying theres no way to tell from the info i sent?
*sigh* nvm..