A block with mass m $=4\mathrm{.}2$ kg is attached to two springs with spring constants kleft $=33$ N$/$m and kright $=56$ N$/$m$.$ The block is pulled a distance x $=0\mathrm{.}21$ m to the left of its equilibrium position and released from rest.

What is the net force on the block at this time $0\mathrm{.}81$ s$?($a negative force is to the left; a positive force is to the right$)$

What is the total energy stored in the system?

If the block had been given an initial push, how would the period of oscillation change?