Answer:
a
b
Explanation:
From the question we are told that
The mass of the rock is
The length of the small object from the rock is
The length of the small object from the branch
An image representing this lever set-up is shown on the first uploaded image
Here the small object acts as a fulcrum
The force exerted by the weight of the rock is mathematically evaluated as
substituting values
So at equilibrium the sum of the moment about the fulcrum is mathematically represented as
Here is very small so
and
Hence
=>
substituting values
The mechanical advantage is mathematically evaluated as
substituting values
