Aflexible shaft consists of a 3 mm diameter steel wire in a flexible hollow tube which imposes a frictional torque of 0.04 n m per meter when the shaft rotates. the shaft is to be used for applying a torque of 0.1 n m to actuate a switch. what is the maximum length of shaft that may be used if the shear stress in the shaft is not to exceed 50 mpa?
Torque is defined as the rotational effect of a force on a body.
The torque T for the maximum shear stress is given as 0.1 Nm
Frictional torque is the torque caused by a frictional force
The frictional torque F is given as 0.04 Nm/m
The maximum length of the shaft is thus given as
L = T / F
L= 2.5 m
no. dot product =0 when vecs at right angles