Four acrobats of mass 75.0 kg, 68.0 kg, 62.0 kg, and 55.0 kg form a human tower, with each acrobat standing on the shoulders of another acrobat. the 75.0-kg acrobat is at the bottom of the tower. (a) what is the normal force acting on the 75-kg acrobat? (b) if the area of each of the 75.0-kg acrobat’s shoes is 425 cm2 , what average pressure (not including atmo- spheric pressure) does the column of acrobats exert on the floor? (c) will the pressure be the same if a differ- ent acrobat is on the bottom?