Physics: Help with Work(concept) When is it applied? 10PTS!!!
Favorites|Homepage
Subscriptions | sitemap
HOME > > Physics: Help with Work(concept) When is it applied? 10PTS!!!

Physics: Help with Work(concept) When is it applied? 10PTS!!!

[From: ] [author: ] [Date: 12-06-17] [Hit: ]
C) Object falls freely from 1.5m above to the floor.- I think yes, because the force of gravity is acting on it, which is 9.8 m/s^2.......

A) An object held 1.5m above the ground.
- Well, it's staying stationary so technically there's no real distance. Distance in terms of Work would be the distance the object moved. This question is only defining distance from the ground. Not really applicable. Also, there doesn't seem to be a force component.

B) Object moves at a constnat velocity (0.5/s horizontally on frictionless surface)
- I'm not too sure about this. Friction was never my favorite part of physics. In order for it to be a work problem you'd have to know at what point it stops (and if it were truly frictionless, wouldn't it not stop?) to find out the distance travelled and it's a constant velocity, not sure if there's any force in that. Also cause force = mass * acceleration. No acceleration, no force, no work.

C) Object falls freely from 1.5m above to the floor.
- I think yes, because the force of gravity is acting on it, which is 9.8 m/s^2. and you have the distnace of 1.5m cuz its actually falling.

So there you go. sorry for the long answer just wanted to make sure you understood everything i was saying and the reasoning. I think your intuition about no acceleration might be correct, since again:

W = Fd
F = ma
and if there's no "a" there's no "f" and no "f' means no "w" as the calculations would keep multiplying to 0.
Like if F = ma, and a = 0, 0 x anything = 0 so f will be zero, and since f is zero w is zero.

-
First of all, work = F * d where d = movement IN THE DIRECTION of the force. So there is no work done if:
- F = 0 (no force)
- d = 0 (no displacement)
- F and d are perpendicular (no displacement in the direction of the force).

"Is work only applied if it accelerates or decelerates?"
Not exactly, though that's a good clue. In order for something to accelerate or decelerate, it has to gain energy or lose energy. Work is a form of energy, so something doing work is usually present in such a situation.
keywords: 10,with,applied,Work,is,concept,PTS,Physics,Help,When,it,Physics: Help with Work(concept) When is it applied? 10PTS!!!
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .