A copper block is dragged across a wooden desk by a spring scale. given that the copper block has a mass of 6kg and that the spring scale reads 12N, find the coefficient of kinetic friction.
what would the answer be?
...Thanks
2006-12-02 07:39:20 · 3 answers · asked by knicksfan000 1 in Science & Mathematics ➔ Physics
One has to first assume the copper block is being pulled at a constant velocity. If so, then the net force on the object is zero. Net forces cause accelerations, and this block would not be accelerating.
Now, the coefficient of kinetic friction is defined as a ration between the force of friction and the normal force on an object. If the table is flat, the normal force is equal to the weight of the object. The weight of the object is found by the equation W=mg, where m is the mass and g is the acceleration of gravity (near the surface of the earth, 9.8 m/s^2)
W = (6kg)(9.8 m/s^2) = 58.8 N = Fnormal
The force of the spring must be exactly equal to the frictional force, because these forces balance to 0. Ffriction = 12N
The coefficient of kinetic friction, therefore, is
Ffriction/Fnormal = 12N/58.8N = .204
2006-12-02 07:48:00 · answer #1 · answered by Nicknamr 3 · 1⤊ 0⤋
did you mean the copper block is dragged with a constant speed or with an acceleration?
2006-12-02 15:44:55 · answer #2 · answered by 7 · 0⤊ 0⤋
assuming the block is travelling ata constant verlocity it would be 12 divided by 9.81 times 6
12/(9.81*)
sorry don't have my calculator on me but that how you do it
2006-12-02 16:52:02 · answer #3 · answered by supremecritic 4 · 0⤊ 0⤋