Design a parallel$-$jaw nut cracker with at least $6$ links. An example containing $7$ links is shown in fig. $2.$ For this particular example, when the force is applied to the handles, the upper jaw link will move downward against the fixed link. When the foregoing motion takes place, line segment AA$$ must remain parallel to line segment BB$.$ Line segment BB$$ should remain horizontal at all times. For your design, the overall size of the nut cracker should not exceed $20$ cm in length, nor exceed a height of $12$ cm when completely open.

$$ Overall length $20$ cm

$$ Overall height $($when fully open$)12$ cm

$$ When a force of $60$ N is applied on the handles, it should crack open a tropical almond nut. Investigate the size of this nut and the energy needed to crack open it$.$