Are both work equations mutally dependent on one another?

[Jbarrie]

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For example if an object has no change in KE, Work=O even though this work equation W=Fd (making up numbers) is W=(10)(5)=50?

When I approach a work equation must BOTH equations(W=Change in KE and W=Fd) be satisfied in order to show work has occurred?

 

[Aerus]

Think about it. If there is no change in kinetic energy, then the object is moving at a constant velocity (it can be any velocity or just at rest (V=0)). That MUST mean that there is no outside net force acting on it (the second equation). Since work is defined as how much net force you are applying on an object over some distance (and we said that there isn't an outside net force), then work is also 0.

If you find a situation where one equation is 0, but the other isn't (on the same object), then you are making some mistake.

In your scenario, force CANNOT equal 10 N, since we said that there isn't a change in Kinetic Energy. If there WAS a net force of 10 N acting on an object over 5 m, then the kinetic energy should have changed.

 

[Jbarrie]

Thank you for giving me a light bulb moment, Your explanation was REALLY helpful 😀
side note: can you say that no force is acting on it because acceleration is zero F=ma?

 

[Aerus]

Thank you for giving me a light bulb moment, Your explanation was REALLY helpful 😀
side note: can you say that no force is acting on it because acceleration is zero F=ma?

What does acceleration fundamentally depend on? It depends on a net force acting on some mass. If there is no net force, then there is no acceleration. You can say the same for the opposite. If there isn't a net force (on some object), then there CAN'T be an acceleration of that object.

We can also relate this to kinetic energy again. Acceleration is simply a change in velocity right? Well if there is no acceleration, then there is no change in velocity. If there isn't a change in velocity, then there isn't a change in kinetic energy.

 

[Jbarrie]

Gotcha thanks a lot for all your help. I have a better conceptual understanding of this subject now 😀!