Net torque about an axis through point A in a massless rod

[paulimerci]

I’m not confused, I thought the reference line represents an arbitrary fixed line (as an x-axis or a polar axis) from which coordinates of a point are computed.

 

[Lnewqban]

I’m not confused, I thought the reference line represents an arbitrary fixed line (as an x-axis or a polar axis) from which coordinates of a point are computed.

Sorry, I misunderstood your picture.

 

[topsquark]

I’m not confused, I thought the reference line represents an arbitrary fixed line (as an x-axis or a polar axis) from which coordinates of a point are computed.

Another way to look at the angle problem is to write the torque equation as $\tau = \textbf{F} \times \textbf{d}$. The magnitude of the torque will be $\tau = F d ~ sin( \theta )$ where the angle is between and measured counterclockwise. To do this draw a quick sketch and place the tails of d and F at the same point.

-Dan

 

[paulimerci]

I’m not confused, I thought the reference line represents an arbitrary fixed line (as an x-axis or a polar axis) from which coordinates of a

Sorry, I misunderstood your picture.

View attachment 317371

Thank you!