0
$\begingroup$

Imagine we have a fulcrum, one side is us and one side is a 20kg weight.

Which one is easier, to push our side's plate downwards to make the other side move upwards, or to lay under the plate and pull it downwards?

$\endgroup$
1
  • 1
    $\begingroup$ You need a plank on the fulcrum and you need to state where the fulcrum is. Assuming there is a plank and the fulcrum is in the centre than it is easier just to sit on it and you need to have mass more than 20kg, also there needs be gravity but it should work on any planet or moon. $\endgroup$ Jan 15, 2019 at 20:13

1 Answer 1

2
$\begingroup$

The question is a broad one with a variety of assumptions built into it. Firstly, we have to know if our fulcrum is in a gravitational field like that of earth or not. If it is in one, then obvoiusly, pulling will be easier. This is because, although the effect will be miniscule, the point on the plank in which the force is applied when pulling downwards is nearer to the core of the earth by a margin equal to the lenght of the plank. Apart from this, generally, pushing downward is easier in the absence of a gravitational field or any other external force. This is because we have to look at the point on the planck that is resting on the fulcrum. This point is obviously on the bottom. So at any given point on the lenght of the planck, say 5m. The point on the bottom of the plank on the 5m mark is closer to the fulcrum than the point at the top of the plank, at the same 5m. Please refer to the picture. And so, since according to the formula for moment of a force, the higher the distance, the greater the moment. So, in abscence of a gravitational field or any other external force, it is easier to push downwards than to pull upwards. Position of points on a fulcrum system

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.