Samuel E. imágenes
img_46_21_two_cars
img_46_20_tilted_towers
img_46_19_tower_pisa
img_46_17_CG_objects
img_46_16_elements
img_46_15_centre_gravity_earth_moon
img_46_14_centre_boxes
img_46_13_wheelchair
img_46_12_centre_gravity
img_46_11_cutting_fingernails
img_46_10_tightening_screw
img_46_9_manpushing
img_46_8_doorknob
img_46_7_rope_pulley
img_46_6_cap_pen
img_46_5_wheelbarrow
img_46_4_pencil
img_46_3_scissors
img_46_2_stool
img_46_1_elements
img_45_16_suspended
img_45_15_truss
img_45_14_truss
img_45_13_truss