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Hyperfluxe
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Homework Statement
Homework Equations
See my work.
Hyperfluxe said:Shouldn't the weights be multiplied by cos(40) because they are vertically downwards, so the moment arm would be the horizontal distance?
Static friction is the force that resists the motion of an object when it is in contact with another object and there is no relative motion between the two. In simpler terms, it is the force that prevents an object from sliding when it is at rest.
When a person walks up a plank, static friction comes into play to prevent the person's feet from slipping and causing them to lose balance. The friction between the person's feet and the plank provides the necessary grip for them to move forward without sliding.
The amount of static friction depends on the coefficient of friction between the two surfaces, which is determined by the materials they are made of. It also depends on the normal force, which is the force exerted by the person's weight on the plank. The roughness or smoothness of the surfaces can also affect the static friction.
The angle of the plank can affect the static friction in two ways. Firstly, a steeper angle will increase the normal force, which in turn increases the static friction. Secondly, a steeper angle also increases the component of the person's weight that is parallel to the plank, providing more force to counteract any potential sliding.
No, the static friction between two surfaces can never be completely eliminated. This is because there will always be some imperfections or micro-level roughness on the surfaces, leading to some amount of friction. However, the amount of static friction can be reduced by using smoother or more slippery materials.