# Why it's easier to push the door from the furthest distance

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THP
Why it's easier to push the door from the furthest distance From the pivot point?

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haruspex
Homework Helper
Gold Member
Why it's easier to push the door from the furthest distance From the pivot point?
Is this a homework question?

THP
Is this a homework question?
Nope

Bestfrog
Try to to think about this: if you want to open/close a door, you have to make the door rotating about the pivot point ##\longrightarrow## you create a torque. The minimum torque ##\tau_m## to open\close the door is equal if you push near or far from the pivot point. So, if ##\tau_m## is constant for each point you push the door, something, like ##r## (distance from the pivot point) and ##F## (the force applied by you), change. In what way?

Yan_Dalton
Another way to say what 'Bestfrog' said,
when you are trying to close a door you produce torque
the torque formula is defined by T = F (the force you make) * d (the distance from the point where the door is atached to the wall, the 'pivot point')
so, the further you push the door from its pivot point, the greater the torque and easier it is to close / open it
(hope you understood it, otherwise just send more questions - this is my first time trying to answer something :) )

haruspex
Homework Helper
Gold Member
I suspect that an argument based on torque does not provide the intuitive explanation that is sought.
Perhaps a more natural way is to think in terms of mechanical advantage. It is effectively a lever. When you push at a point far from the pivot you have to push further to get the door to close to the same extent. This spreads the effort over a greater distance. It is like walking up the long but gentle ramp instead of climbing the short flight of stairs.

THP, DS2C, Yan_Dalton and 1 other person
Yan_Dalton
I suspect that an argument based on torque does not provide the intuitive explanation that is sought.
Perhaps a more natural way is to think in terms of mechanical advantage. It is effectively a lever. When you push at a point far from the pivot you have to push further to get the door to close to the same extent. This spreads the effort over a greater distance. It is like walking up the long but gentle ramp instead of climbing the short flight of stairs.
"It is like walking up the long but gentle ramp instead of climbing the short flight of stairs."
Very nice way to explain, thanks for the reply man :)