My experiment setup was like this:
i48.tinypic. com/14n31pl.jpg
FYI, there is sandpaper between the ruler and the wall. I calculated the coefficient of friction to be 0.468. Is that correct?
A second question asks that as the hanging weight is moved closer to the wall, what other variables change (tension, normal or horizontal force, friction or vertical force, coefficient of friction) and which remain the same? I'm not sure. Is it the friction that increases as the torque caused by the hanging weight increases? And everything else remains the same?
I'm sorry, but I am currently unable to view images. However, I can still help answer your questions based on the information you provided.
To determine if the calculated coefficient of friction is correct, we need to understand how it was calculated. The coefficient of friction, denoted as μ, is a dimensionless quantity that represents the frictional force between two surfaces in contact. It is defined as the ratio of the frictional force to the normal force between the surfaces.
In your setup, since there is sandpaper between the ruler and the wall, the frictional force between them can be measured by the force required to move the ruler along the wall. The normal force is the force exerted by the wall on the ruler, perpendicular to the contact surface.
To calculate the coefficient of friction, you would measure the force required to move the ruler (the frictional force) and divide it by the normal force. If you have already done this and obtained a value of 0.468, then that would be your calculated coefficient of friction.
Regarding your second question about the variables that change as the hanging weight is moved closer to the wall, let's analyze each variable:
1. Tension: As the hanging weight is moved closer to the wall, the tension in the string or wire supporting the weight will increase. This is because the distance between the weight and the wall is decreasing, causing the vertical component of the tension force to increase.
2. Normal or horizontal force: The normal force between the ruler and the wall will remain the same. It is determined by the weight of the ruler acting perpendicular to the wall.
3. Friction or vertical force: The frictional force between the ruler and the wall may change depending on the coefficient of friction and the normal force. If the weight is moved closer to the wall, the normal force will remain the same, but the coefficient of friction could potentially change if the contact surfaces between the ruler and the sandpaper or wall are altered.
4. Coefficient of friction: The coefficient of friction should remain the same, assuming the contact surfaces and conditions between the ruler and the wall remain constant. It represents the inherent frictional properties between the surfaces in contact and does not directly depend on the position of the hanging weight.
In summary, as the hanging weight is moved closer to the wall, the tension increases, while the normal force remains the same. The frictional force and the coefficient of friction may also change depending on the specific conditions, but if everything else remains constant, the coefficient of friction should remain the same.
Remember that this is just a general analysis, and the actual behavior of the variables might depend on the specifics of your experiment and setup.