22. what is the force exerted by a pressure of 720 lb/in? on a hydraulic piston with a
radius of 1.5 inches? (first: use the area formula for a circle (a = ar to get the surface
area of this circular piston.)

Julia would be observing a. static electricity was caused by her sweater rubbing against her shirt and transferring electrons. she didn't touch anything metal, so that would cancel out b.she most likely didn't rub her sweater against her hair either, so that cancels out c.she also didn't scoot across the carpet while trying to take her sweater off, that cancels out d.so that leaves a.a. is correct.