Gyan ki baat

 A simple quick return mechanism is shown in the figure. The
forward to return ratio of the quick return mechanism is 5:3 If
the radius of the crank O1P is 145 mm, then the distance
‘d’ (in mm) between the crank centre to lever pivot centre
point should be.

ANS :

  

Write the given data , Draw the sketch according to Given Condition.

Here the ratio of forward to backward is 5:3

👉 5/3 =(360° - aplpha) / Alpha

👉 find the value of alpha 

i.e Alpha =______

After that (Alpha)/2 = ______

From figure , triangle

Solve further process ..