Question
What is torque? Write its formula in vector form. Handle, to open the door, is always provided at the free edge of a door. Why?
✓
Answer
Torque is the moment of force. It is written as the cross –product of the position vector of the point of application of the force and the force, i.e.,
$\vec{\tau}=\vec{\text{r}}\times\vec{\text{F}}$
It is measured in Nm and has dimensions of ML2T2. Since, $\tau=\text{rF}\sin\theta,$
where $\theta$ is the angle between $\vec{\text{r}}\text{ and }\vec{\text{F}},$ it is also said, torque is the product of the perpendicular distance between the axis of rotation and point of application of force in line with the force. It is the cause of rotational motion. To open the door, handle is to be rotated. So we need a torque. With less force one can exert more torque if the handle is at the edge.
$\vec{\tau}=\vec{\text{r}}\times\vec{\text{F}}$
It is measured in Nm and has dimensions of ML2T2. Since, $\tau=\text{rF}\sin\theta,$
where $\theta$ is the angle between $\vec{\text{r}}\text{ and }\vec{\text{F}},$ it is also said, torque is the product of the perpendicular distance between the axis of rotation and point of application of force in line with the force. It is the cause of rotational motion. To open the door, handle is to be rotated. So we need a torque. With less force one can exert more torque if the handle is at the edge.
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