The Importance of Friction
Friction is almost always necessary in ballet, but the dancer must apply the correct amount of friction for her movement’s to be successful.
In the example of the dancer as she begins her leap (as explained in the previous page), the dancer needs friction so that she can push against the ground, because this friction allows her to accelerate forwards and upwards, due to Newton’s third law. As was explained in the previous page, the friction of the dancer pushing against the ground in a backwards and downwards motion has an equal and opposite reaction, causing the dancer to move forwards and upwards as she leaps. If the dancer used no friction then there would be no force allowing her to accelerate forwards into her leap, so she would not be able to move forwards and properly perform her leap. To increase the friction the dancer must push down and backwards with her back foot with a lot of strength. This friction is necessary because the longer the dancer is in the air moving forwards, the more time she has to lift her legs up high into the correct position, before she is brought back to the ground. If the dancer doesn't also push down into the ground with enough strength then the equal and opposite reaction that causes her to leap into the air will not be strong enough and this will mean that she is unable to get her legs high enough before falling to the ground.
In the example of the dancer as she begins her leap (as explained in the previous page), the dancer needs friction so that she can push against the ground, because this friction allows her to accelerate forwards and upwards, due to Newton’s third law. As was explained in the previous page, the friction of the dancer pushing against the ground in a backwards and downwards motion has an equal and opposite reaction, causing the dancer to move forwards and upwards as she leaps. If the dancer used no friction then there would be no force allowing her to accelerate forwards into her leap, so she would not be able to move forwards and properly perform her leap. To increase the friction the dancer must push down and backwards with her back foot with a lot of strength. This friction is necessary because the longer the dancer is in the air moving forwards, the more time she has to lift her legs up high into the correct position, before she is brought back to the ground. If the dancer doesn't also push down into the ground with enough strength then the equal and opposite reaction that causes her to leap into the air will not be strong enough and this will mean that she is unable to get her legs high enough before falling to the ground.
Too much friction is also bad in ballet. For example, when a dancer is doing a pirouette there is friction between her foot and the floor, which stops her from spinning to fast and/or losing control and falling. When there is too much friction (for example, if the floor and the dancer’s shoes are very sticky) then the dancer's foot wouldn’t be able to turn around fast enough. There will be more friction than thrust and the dancer will decelerate, and she will be unable to turn around fast enough to properly complete her pirouette.
However, if there is too little friction (for example, if the floor and the dancer's shoes are very slippery) then the dancer is unable to maintain a grip on the floor and she will slip over, or spin too fast, losing control of her turn and falling over. This is why it is important to apply the correct amount of friction in ballet, as too much or too little will cause the dancer's movements to be ineffective. To increase friction when doing a pirouette, the dancer can apply water to the soles of her ballet shoes. This will her shoes more sticky, so her shoes will stick to the ground more and thus increase the friction. To decrease the friction the dancer must ensure she is up high on demi-pointe, (on the ball of her foot). This reduces the surface area of her foot that is on the ground, which means there will be less friction. The dancer must be up high on her supporting leg and correctly working the muscles so that she is high on demi-pointe as she turns. The type of dance shoe and the stickiness of the floor will also determine the amount of friction as the dancer turns. |
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