Science
jowhite:

In which example is no work done on an object? A. pushing against a sturdy brick wall B. lifting a plant on to a table C. pushing a heavy desk on the carpet until it moves D. pulling horizontally on a rolling suitcase

SmokeyBrown:

Let's keep in mind that for work to be done on an object, the object has to move (or be "displaced") a certain distance. No displacement means no physical "work", even if energy is used. So, which of the answer choices does not involve the object actually moving?

jowhite:

Idk im confused

jowhite:

SmokeyBrown:

No worries. If you break down the formula for "physical work", you could say that work is equal to the Force you exert on an object multiplied by the Distance that the object moves in the direction of the Force. Or, in a simpler way: Work = Force * Distance So, if the object does not move any distance, there is *no work* done. In the answer choices provided, 3 of them *do* involve using force to move an object. But then, in one of the answer choices, a force is exerted on an object, while the object *does not* move. Can you identify which choice that is? It would not be B, since the plant in that answer choice does move, to the table

jowhite:

No

jowhite:

SmokeyBrown:

A sounds like a good choice! No matter how much you push on the sturdy brick wall, it won't move (unless you're superman lol). No motion means no work, so I think you've found your answer. Well done :)

jowhite:

Thx

SmokeyBrown:

Np