A Boeing 747 cruises at \(M=0.87\) at an altitude of \(13 \mathrm{~km}\) on a standard day. A window in the cockpit is located where the external flow Mach number is 0.2 relative to the plane surface. The cabin is pressurized to an equivalent altitude of \(2500 \mathrm{~m}\) in a standard atmosphere. Estimate the pressure difference across the window. Be sure to specify the direction of the net pressure force.