Login

Q.7 Why are doors provided with handles near the outer edges, far away from the hinges?

Dear Student 

We know Torque = F r sinϴ​
To open a door a minimum torque has to be obtained since sinϴ is alredy at max in door we either need to increase F or r. If the knob were near the hinges, you would have to pull harder this is because the torque(twisting force) has decreased. By placing the knob (the point of applied force on the lever) as far away as possible from the hinges (the fulcrum of the lever), the smallest force is required to open the door because the force you are using causes a lot of torque around the hinges.

Regards

 

  • 0
View Full Answer
The reason is due to torque. The door will rotate around the hinges. If you pull on a door handle with a certain amount of force and the handle is 1 foot away from the hinges , you will provide a certain amount of torque to open the door. If you pulled with same force on a handle that is 2 feet away from the hinges, you will provide twice the torque, so it will be twice as easy to open. So you want the handle as far from the hinge to make the door as easy as possible to open. Torque = force x distance
  • 5
What are you looking for?