# Physics problem help

• 11-26-2007, 07:16 PM
Chrono6456
Physics problem help
I have a test tomorrow and Im just reviewing now and have stumbled upon a simple problem and am stuck.

Im sorry if its really simple, im just having a brain freeze on it right now

If 2 J of work is done in raising an apple 180g, how far is it lifted.

I know you use Work=(Force)(distance)

Is F supposed to be approximately 1.8 N? So then the answer is 1.111M? I dont have the answer in the back of the book, its an even number
• 11-26-2007, 07:34 PM
-chw42-
What does J stand for again?
• 11-26-2007, 07:35 PM
Chrono6456
joules
• 11-26-2007, 07:38 PM
-chw42-
Ah! Not Chemistry again, sorry I don't think I'm far enough in my first year of Honors Physics to figure that out...
• 11-26-2007, 07:40 PM
Soulphalanx
yeah, take grams of the apple and multiply by 9.81 for the acceleration of gravity. (F=ma)
then take Work and divide by force to get your Distance (Work = Force X Distance)
• 11-26-2007, 07:44 PM
-chw42-
Quote:

Originally Posted by Soulphalanx
yeah, take grams of the apple and multiply by 9.81 for the acceleration of gravity. (F=ma)
then take Work and divide by force to get your Distance (Work = Force X Distance)

Wouldn't it be 9.8 or -9.8 depending on the direction?
• 11-26-2007, 07:55 PM
Soulphalanx
yes, however, the apple is lifted.
assuming gravity is in the negative direction
working done lifting the apple is in the positive direction

and also the fact that its only used to determine the weight of the apple
Cant really have a negative weight now can we
• 11-26-2007, 07:58 PM
psp11
Quote:

Originally Posted by -CHW42-
Wouldn't it be 9.8 or -9.8 depending on the direction?

It doesn't really matter if you use a -9.8 or +9.8 for gravity in this situation since the question says you are lifting the object...
• 11-26-2007, 08:04 PM
Chrono6456
k, problem solved, thanks