Work on an object moving downards

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Homework Statement

You move a textbook from a high shelf to a low shelf. Is the work you do on it positive or negative?

Homework Equations

W = Fcosd

The Attempt at a Solution

My understanding is that if you are doing a positive applied force on the textbook, over some distance, the work should be positive. But the answer is negative. Why?

 

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In what direction is the force YOU exert? Compare this with the direction of motion.

 

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In what direction is the force YOU exert? Compare this with the direction of motion.

The motion is upwards, the direction is downwards.

 

[brainpushups]

upwards

That's not how you phrased the question:

You move a textbook from a high shelf to a low shelf. Is the work you do on it positive or negative?

From a high to a low shelf means the motion is downward. The force you exert is upward. Therefore the work you do is negative (force and displacement are in the opposite direction i.e. θ = 180)

 

[AAAA]

That's not how you phrased the question:
From a high to a low shelf means the motion is downward. The force you exert is upward. Therefore the work you do is negative (force and displacement are in the opposite direction i.e. θ = 180)

Right, sorry! I meant the force is upwards. Yes, I understand now. Thanks!