~~~acceleration In One Dimension~~~

[Faiza]

I didn't get any replies :cry: , this is due monday, i still dun understand the concepts and all the new concepts are built on the previous ones! :frown:

I was wondering if an object can have a negative acceleration and be speeding up? If so, can you describe a possible physical situation and a corresponding coordiante system, If not can you explain to me why not?

[faust9]

A negative acceleration means the direction of the acceleration is toward the negative side of your chosen coordinate system. If you decide that all bodies accelerating to the left have positive acc then a body that accelerates to the right would have negative acc. This does not imply that the bodies are slowing down though.

Example: Falling bodies. Typically we define up as positive and down as negative. Drop a ball from a cliff using conventional coordinate system and the ball will have negative acceleration and have increaseing velocity.