Newton's Third Law of Motion
Newton's Third Law of motion can be associated with balancing and leaping. There are two essential parts of physics required for a dancer to balance.
An important concept to understand when analyzing balancing is the dancer's center of gravity. As mentioned before, when a dancer has both feet on the ground, it is easier to maintain a solid center of gravity. In order to do so, the dancer's contact with the floor must be directly below their center of gravity. However, if a dancer fails to keep their center of gravity directly above the contact with the floor, their "unbalance" will create angular acceleration and he or she will fall. It is harder for a ballet dancer, for instance, to balance, if he or she is on pointe because there is a smaller area in which he or she is able to find their center of gravity. Some technicalities dancers to do maintain a net force and torque of zero, is through the placement of arms and their torso. |
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Does Newton's Third Law apply to balancing while turning?
Of course! There is such complexity to turns (as discovered in the exploration of Newton's Second Law of Motion). Let's refer to turns as either slow or fast. When performing a slow turn, the upwards force of the floor and downwards force of gravity still exists. Therefore, it is important to maintain static balance during a slow turn. When performing a fast turn, the same normal force and force of Earth are applied but the dancer must keep a "solid" axis of rotation so that they are not turning in uncontrollable directions. It is important to note that it is impossible for a dancer to achieve static balance during a fast turn because of the force of torque. On the page about Newton's First Law of motion, the concept of leaping was explained. It was stated that before a leap, the dancer has to apply a force to the ground that will determine the height, length, and floating effect of the leap. This principle can also be associated with Newton's Third Law. The force that the dancer applies to the floor before the leap is equal to the force that the floor applies to the dancer.
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