E
Ev H
Guest
I'm working on an Investigation (Experiment, Report) for my grade 11 Physics course, and there is one question I just don't know how to find the answer to.
The question is: Calculate the average kinetic coefficient of friction for the two surfaces you used. What could you do to reduce this value?
The experiment consisted of me dragging objects across a carpet ontop of a kleenex box. I was holding onto an elastic band, and the length that it stretches is directly proportional to the magnitude of the force provided by the elastic band. So I have all the measurements of how far it stretched, the weight of each object, and the mass of each object. I also have an equation (Hooke's Law) to find the spring constant of the elastic band, which is
F=kx
Where k is the spring constant and x is the displacement of the band. I can find the spring constant by having an object with a known mass attached to the elastic by using Fg=Mg.
This is where I get confused because Fg=Mg says that the force of gravity is the same as the force on the elastic band, which doesn't make any sense to me. I also don't know where to go from there, since the equation for finding the kinetic coefficient of friction for the surface is:
Ff=uFn
Where Ff is the force of friction, u is the kinetic coefficient of friction and Fn is the normal force, or in this case is equal to Fg.
But to find the kinetic coefficient I have to know the force of friction, which I don't understand how to find. I'M SO CONFUSED.
Please help me! This is one of the key questions that I have to hand in to be marked for this unit, and I would be eternally grateful. THANK YOU SO MUCH in advance to anyone who is amazingly brilliant and can try to help me. Any guidance is much appreciated!
The question is: Calculate the average kinetic coefficient of friction for the two surfaces you used. What could you do to reduce this value?
The experiment consisted of me dragging objects across a carpet ontop of a kleenex box. I was holding onto an elastic band, and the length that it stretches is directly proportional to the magnitude of the force provided by the elastic band. So I have all the measurements of how far it stretched, the weight of each object, and the mass of each object. I also have an equation (Hooke's Law) to find the spring constant of the elastic band, which is
F=kx
Where k is the spring constant and x is the displacement of the band. I can find the spring constant by having an object with a known mass attached to the elastic by using Fg=Mg.
This is where I get confused because Fg=Mg says that the force of gravity is the same as the force on the elastic band, which doesn't make any sense to me. I also don't know where to go from there, since the equation for finding the kinetic coefficient of friction for the surface is:
Ff=uFn
Where Ff is the force of friction, u is the kinetic coefficient of friction and Fn is the normal force, or in this case is equal to Fg.
But to find the kinetic coefficient I have to know the force of friction, which I don't understand how to find. I'M SO CONFUSED.
Please help me! This is one of the key questions that I have to hand in to be marked for this unit, and I would be eternally grateful. THANK YOU SO MUCH in advance to anyone who is amazingly brilliant and can try to help me. Any guidance is much appreciated!