For example, dry steel on dry steel has a static coefficient of about 0. If this does happen, then it can be safely concluded that my conclusion and results were accurate.
This is very good.
Ask students to individually write paragraphs explaining how and why weight affects normal friction, and how and why contact area affects friction due to molecular attraction. It was also very difficult to get a good constant contact between the coins and putty.
When electrons move through a short piece of resistance putty, they would only feel resistance for a short amount of time compared to a longer piece. If this had happened, this result would not have been calculated in with the other two resistance values to produce the average resistance.
Therefore, the longer the resistance putty, the greater the total of resistance there will be. Similarly, more force is required to keep the body in motion when gravity acting on the added weight tends to re-engage the peaks and valleys.
So, the amount of area in contact does not seem to matter when it comes to friction.
The discussion following their experiments should also have raised questions about the roles of weight and contact area in the amount of friction that occurs between two surfaces.
So, as long as the surfaces are relatively uniform, meaning they do not change in microscopic texture from one region to another, the amount of area in contact does not affect the frictional force.
More essays like this: Every pair of surfaces has a unique, empirically obtained set of coefficients. If the graph was a straight line going through the origin, it would show that the results were directly proportional i. Ask the students to speculate on why these two materials, which are similar in appearance, have such different coefficients of friction.
The coefficient of friction between two surfaces, because it is empirically derived and based on numerous experiments, reflects the largest peaks and valleys typical of the two surfaces involved.
This might not seem to make sense at first. Friction between a coffee mug and a formica countertop. For these materials, the amount of friction that occurs can, in fact, be affected by the amount of surface area in contact, although at this point the nature of the molecular attractions involved is poorly understood.
But the resistance is still increasing, just at a different rate. Point out to students that many aspects of friction are still poorly understood and are being researched by scientists and engineers throughout the world. Show students a copy of the coefficients of friction table included in this section for comparison.
And as long as a few peaks and valleys are getting hung up on each other, it makes no difference if other peaks and valleys are also getting hung up simultaneously—as long as these additional peaks and valleys are not bigger than the original set of some peaks and valleys.
Since it is mainly engineers who use these values, most coefficients found in reference materials are related to machinery and automotive applications. But, even though this problem occurred, I tried to do the experiment in as safe an environment as possible. The amount of surface area in contact does not appear in the equations anywhere.
These experiments would still involve changing just one variable, but instead of having a constant width of 2cm in diameter, the constant width could be 5cm in diameter instead. By looking at my results, they look quite reliable. Apart from this, my repeated resistance values for the different lengths are approximately in a range of about 1?
We know that for resistors in series, the total resistance is equal to the sum of all the individual resistors. However, consider that as long as some surface imperfections are present on one or both surfaces, friction will occur.
This could be due to the readings constantly fluctuating and the current reading being too small.For the second example, students might argue that, "Weight will not affect the amount of friction because the same amount of surface on the bottom of the cup will be in contact with the table's surface.
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My task is to investigate the factors that affect the terminal velocity of a falling object. Key Factors · Mass of ball bearing · Viscosity/density of the fluid · Surface area of ball bearing · Texture of the balls surface · Temperature I am going to investigate how mass affects the terminal velocity.
What Factors Affect Movement?
Specific Curriculum Outcomes Students will be expected to: • investigate factors that affect movement [GCO 1/3] • propose an answer to an initial question or problem and draw a simple conclusion [GCO 2] • communicate procedures and results. There are three different factors, which may affect the resistance of resistance putty.
These three factors are temperature, length and thickness. To investigate the temperature it is very hard to make the temperature go up/down in certain intervals, it’s also hard to connect the connecting wires to the putty itself.
An experiment to investigate the factors which affect Resistance in a wire What is resistance? A potential difference (V) applied across a wire of length (l), there is in the conductor, an electric field (E).Download