How can I create force on one end of an object using mouse dragg whose other end is fixed

Questions & Answers
1

72063-spring.jpg

I want to bring down the B point of AB object and the spring will help it return back to its initial position.
I fixed A point using a Hinge Joint, but can’t handle the remaining part. Actually I want to know how can I dragg the B point down using mouse.

2

You can rotate an AB object with pivot centered on point A.