#$4)$ Dr$.$ Sachiko McBride created a hydraulic lift system that has, on the left side, a small piston with a radius of $0\mathrm{.}0045$ m and on the right side, a larger piston with a radius of $0\mathrm{.}085$ m $($the two pistons are connected by a small tube at the bottom and have the same initial heights$).$ She puts some walnuts on the small piston on the left side. Two squirrels, Jackie and Half$-$tail, try to get walnut by teamwork $($they can't reach the walnut since the piston hole is too small to stick their heads in and their arms are too short$).$ So$,$ Jackie stands on the large piston to raise the walnut on the small piston. The mass of Jackie is $0\mathrm{.}13$ kg $.$ The mass of the walnuts are negligible.

$($A$)$ What is the pressure in the fluid as a result of Jackie standing on the large piston? $[$Final answer should be in units of Pascal$]$

$($B$)$ As a result of Jackie standing on the larger piston, calculate how much upward force is transmitted to the smaller piston to raise the walnut for Half$-$tail?