Aforce of 21.0 n is required to start a 2.8 kg box moving across a horizontal concrete floor. (a) what is the coefficient of static friction between the box and the floor? (b) if the 21.0 n force continues, the box accelerates at 0.50 m/s2. what is the coefficient of kinetic friction?

(a)

Assuming the box is on a horizontal surface, the Normal Force would be equal to the Gravitational force which is 2.8 * 9.8 = 27.44N. You are already given the force, so we are ready to solve:


Since a coefficient of friction doesn't have units, your answer is 0.77.

(b)
We can use F = ma to get the Force, and then the same Normal force to get the kinetic coefficient of friction.



We can use that to formulate the kinetic coefficient of friction:



And those are your answers. Hope this helps. I'm not a college student, but I'm taking AP Physics, so I have an idea.

Answer: buoyancy forceexplanation: in simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational acceleration, g. this is also known as upthrust.

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