Question

Why are door handles usually as far away
as possible from the hinges ? What does this
tell you about the factors on which the turning
effect of a force depends ? Hence define the
moment arm of a force.​

Answer 1

Answer:

so that the force can be reduced for opening the door

Answer 2

$\rule{200}{2}$

$\huge\boxed{\boxed{\underline{\mathcal{\red{A}\green{N}\pink{S}\orange{W}\blue{E}\pink{R:-}}}}}$

Turning a door requires the least force when it is applied as far away from the rotation axis of the hinges as possible. So, handles on doors are put as far away as possible from the hinges. Also, it is easier to turn a door if the force is applied perpendicular to the rotation axis.

Thus turning effect of a force or torque depends the magnitude of the force, its direction and point of application.

For a measure of the turning effect of a force Juing in a plane perpendicular to the axis of rotation, te must consider the magnitude of the applied force and the distance of its line of action from the axis.

$\bf\large\underline\green{Definition:-}$ : The perpendicular distance from the axis of rotation to the line of action of the force is called its moment arm or lever arm.

$\rule{200}{2}$