The two trees are (l)m distance apart. A backpacker is trying to lift his pack out of the reach of bears. Calculate the magnitude of the force (FT)newtons that he must exert downward to hold a (m)kg backpack so that the rope sags at its midpoint by (y)m distance.

Link to a Mathjax code of a quadratic equation.

a)

Please enter the following data to calculate the previous equation: