21Stage A Stage B Stage C Stage D Fnet = ma Fnet = 0 N Fnet = 400 N, up Stage BStage CStage DFnet = maFnet = 0 NFnet = 400 N, upFnet = 400 N,downFnet = 784 N,FN equals FgFNorm = 784 NFN > Fg by 400 NFNorm = 1184 NFN < Fg by 400 NFNorm = 384 NFN < Fg by 784 NFNorm = 0 N
22This last situation is the reasoning you might feel a little queasy in the stomach when you go over a good size bump in the road at a really fast speed or sudden drops on roller coasters. You catch a little air and the seat drops out from you briefly.
23Rather than define weight as the force of gravity that acts on you. We can say that it is the force you exert on a supporting floor.
24WeightlessnessIs not the absence of gravity, rather it is the absence of a support force.
25Newton showed that the ocean tides are caused by differences of the moon’s gravitational pull on opposites sides of the earth.
26When the sun, Earth, and the moon are all lined up, the tides due to the moon and sun coincide.
27These are called spring tides. Resulting in higher than average high tide and lower than average low tides.These are called spring tides.