Question

Mechanics Help Please
A fixed end tube is 50 mm long. In the middle of the beam a 15mm long lever is attached. A force of 20 N is applied at the end of the lever. If the polar moment of area of the tube = a mm^4 and the Shear Modulus of the material = p N/mm^2
Calculate the angle through which the tube rotates.

I understand that I need to use T/J = Gθ/L but I am unsure what to do about the torque being applied in the middle?
Thank you

Answer 1

I think that the requested torque \(M\), is:
\(M= l \cdot F=15 \times 20=300\)\(N\cdot mm\)

Answer 2

since we have to consider the torque of the force \(F\) with respect to the axis of the beam

Answer 3

here is the situation described by the question:

Answer 4

The drawing thing isn't working for me but in the lecture the tube was along the X axis, the lever coming out was in the z axis and the force acted in the y axis. I'm just going to swap to a different browser and see if I can get the drawing to work
Thank you

Answer 5

we need to know this distance:

I think that we can approximate the distance \(d\) with the length of the lever