Work, force and displacement directions

In summary, The conversation discusses a question about whether a certain physical situation is possible based on given forces and displacement. The conclusion is that there could be other factors at play and the assumption cannot be made unless specified.
  • #1
SecretSnow
66
0
Hi guys! I stumbled upon this truly weird question that seems counter intuitive to me. For the purpose of this question, I'll use x,y,z as unit vectors without the roof because I'm using my phone now..
If F= 160N x - 40N y and s= 14m x +11m y (as stated in the question) is this physically possible? I mean, the y-force is in the negative direction which I would take as downwards, and the displacement is actually positive, or upwards! Continuing this question, using scalar product method, I get 1800J as my answer. Thanks!
 
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  • #2
There are several ways this situation could come about. For example there could be other forces acting that you aren't told about, or the object being acted on by F could have some initial velocity and thus momentum in the y-direction. Unless you're specifically told that the object starts from rest, you can't make the assumption.
 
  • #3
gneill said:
There are several ways this situation could come about. For example there could be other forces acting that you aren't told about, or the object being acted on by F could have some initial velocity and thus momentum in the y-direction. Unless you're specifically told that the object starts from rest, you can't make the assumption.

Yes, you're right. The question didn't specify that this is the only force. Thanks bro!
 

FAQ: Work, force and displacement directions

What is work and how is it calculated?

Work is the product of force and displacement. It is calculated by multiplying the magnitude of the force applied in the direction of motion by the distance over which the force is applied.

What is the difference between work and power?

Work is the amount of energy transferred when a force is applied over a distance. Power, on the other hand, is the rate at which work is done, or the amount of work done per unit of time.

How do you determine the direction of work in a given situation?

The direction of work is the same as the direction of the force applied. If the force and displacement are in the same direction, work is positive. If the force and displacement are in opposite directions, work is negative.

What is the relationship between work and displacement?

The work done is directly proportional to the displacement. This means that if the displacement increases, the work done also increases, assuming the force remains constant.

Can work be negative?

Yes, work can be negative. This occurs when the force and displacement are in opposite directions, resulting in the work done being negative. This means that energy is being taken out of the system rather than being put into it.

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