Question

What are the rate of change of momenta of the pendulum bobs 1 and 2 as observed from the reference frames A and B respectively Find the net forces acting on the bobs relative to A and B in each case find the tension in the strings as viewed by both observers.

Answer 1

For the observed A, the FBD of the bodies 1 and 2 are given since no force acts horizontally the rate of change of their momenta is zero The vertical forces T and mg are balanced
For the observer B, the FBD of the bodies 1 and 2 are given. The pseudo forces ma acts on each bodies to left Hence, the net force acting on each body will be equal to `-ma` which is numerically equal to the rate of change in momentum of the bodies as observed by B.