Friction Lab

Experiment 1: How Hard Surfaces Press Together
How does normal force affect the force of friction and what factors contribute to that?
IV: Normal Force
DV: Force of Friction
CV: Constant speed, same object, same surface

Prediction: As the Normal force increases, the force of friction increases proportionally.

Apparatus:
- Block with two different types of surfaces
- force meter
- different amounts of weight
- Logger pro

Procedure:
1. Attach the block with two surfaces to force meter and plug it in to the computer.
2. Pull the force meter that is connected to the block with two surfaces, horizontally.
3. Use logger pro to write down the mean amount of newtons it took to pull the block from meter.
4. Add weight gradually to see how the added weight affects the force of friction.
5. Collect data and see how it affects the force of friction
6. Convert miligrams to gramsgrams to kg by diving by 1000 then multiply by 9.8N/kg to get newtons.
7. Turn block over and use the other surface of it
8. Repeat steps 1-5

Data Collection:

VM: As the Normal Force increased (N), the Force of friction (N) increased proportionally.
MM: Force of Friction = (0. 3744 N/N) Normal Force + 0.1156 N
Slope: For every Newton of normal force, the force of friction increased 0.3744 N.
Y-int: When normal force is at 0, force of friction is at 0.1156 N

VM: As Normal Force increased (N), the force of friction increased proportionally
MM: Force of Friction = (0.3029  N/N) Normal Force - 0.146 N
Slope: For every Newton of normal force, the force of friction increased 0. 3029 N
Y- int: When normal force is at 0, force of friction is at -0. 146 N.

Conclusion:

We were trying to find out in this experiment, what factors went into how normal force affected the force of friction and what degree of effect took place. We found out that the increase of normal force, through the added weight on the block led to a proportional increase in force of friction. This also showed that the different surface also affects the amount of friction force is in effect. With the vinyl there was a larger force of friction than the felt because they were different surfaces used. Our variables for the experiment were the force of friction and normal force. However, the way were able to change the normal force to see how it affected force of friction was by adding different weights to the block and seeing how it affected the force of friction.very nice

The thing that was the same for everyone's graph was that everyone's force of friction grew proportionally with the added weight. What was also the same was that the vinyl force of friction was higher than the felt force of friction. What was different was the slope of everyone's graph. This may be because people tried to be as accurate as they could with the mean average of the force of friction.
but the slopes were roughly the same for everyone

Drawing Conclusions:

Two people wearing identical shoes can have different forces of friction if they have different normal forces. This is true because with a different normal force is also different weight of each person. If they have different weights, they may also have different forces of friction because as normal force increases, the force of friction also increases.

Two people who have different shoes can have the same forces of friction by the same principle. If the person has a larger weight but a smoother shoe surface that may be the same force of friction on someone with a lighter weight but with a rougher shoe surface.perfect

Force of friction  is affected by type of surface and how surfaces are pressed together
Not affected by velocity or surface area
Slope = coefficient of friction tells you about the type of surface

Errors:

One source of error is the fact that we could've taken data with more different weights. This would allow us to see how the affect of normal force would affect force of friction over more weight instead of having to extrapolate data. This would allow for a more accurate graph and less variability in slope. The second error was that we only did one experiment on each side. We could do the experiment again, this time adding more weights and seeing if the data from the previous experiment still holds true with the data of the second time we do the experiment. This, too, would allow for a more accurate reading of the experiments.

Journal Statement:

I feel I am becoming better at writing lab reports because I am able to remember what things are needed to include in the reports. I am able to write verbal and math models more easily and even more so, help my lab partners with theirs because it helps with the collective understanding of the lab report format. excellent - they too said you were helpful :)  I could improve my writing by getting back critiques on even the most minute mistakes because I want to perfect my lab reports and in the same way be able to write lab reports without having to look at previous lab reports as reference. great job!

Gravity Force Lab

Objective:
Our objective was to see how mass affects gravitational force. We wanted to see if it positively affected, negatively affected, or had no affect on the gravitational force.

Plan:
We would test this theory by using the force meters that were given to us in class. We would hook them up to the laptop that had logger pro and use that to see how weight had affect on the number of newtons acting on the force meter. We would attach weights to the bottom of the force meter of various weights and then write down in a data table what the newtons were in relation to each differing mass. Once we found that, we would use the information in the data tables to create a graph with the mass that is measured in kilograms on the x-axis and force, measured in newtons on the y-axis. Once the dots are plotted, we would make a line representing the direction of the correlation. We would make this graph by putting the point in Xcel and having the program graph the line and give us the formula that the information would provide.  good

As you can see from the data table, we used differing weights that were, at first, twice as much as the previous, but the last weight is only 0.1 kg larger than the previous because we could not double the previous weight. However, as seen from the graph, there is some sort of correlation between the mass (kg) and the force that is attributed to that mass.
title the graph

VM: As the mass (Kg) increases, the force of gravity (N) increases proportionally. 

MM: Force = (9.8298 N/Kg)mass + 0.0076 N 

Slope: For every kg the force increased 9.8298 N.

Y-int: When mass is at 0, force is at 0.0076 N. 

very good

Claim/Evidence/Conclusion

The force increased proportionally with the increase of mass. The graph shows that each time more weight mass was added to the device, the force of gravity increased with it. There was no decrease with the increase of mass. The difference between mass and weight is a very difficult concept to grasp. In the simplest and most easy to understand terms, mass is how much stuff is in something and weight is the force of gravity that is acting on an object. Subsequently, all things with mass have a corresponding weight. All the graphs are the same because we are all on the planet Earth. All the masses that we measured in relation to force we measured by how much of the Earth's gravity is acting on the object. They each have a different force of gravity, however the force of gravity is proportionate to the mass and therefore is a constant increase in the graph. very good - just state how much the increase is!  And the new equation - This also explains why light and heavy objects all hit the ground at the same time. With the different forces of gravity, their is also a different mass of object. Consequently, objects of larger mass have bigger weight. This mass to weight ratio, if put against another object of a lighter weight and less mass would be proportionate to the other. Thereby, allowing both to fall to the ground, and hit the ground at the same time. excellent!

Dueling Buggies Lab

Objective Statement:
What we are trying to do and accomplish in this lab is to first find the constant velocities of each buggy. Once that is found, we must use those velocities to calculate, from a certain distance apart from each other, where they would meet in centimeters. The distance would be measured centimeters.

Plan:
We decided we would first find the constant speed of the slow buggy and then the speed of them in comparison to the other buggy, the faster buggy. We would do this by starting each one on one side of a meter stick. Then we would see how long it would take in second for the slow buggy to reach the end of the meter stick also known as 100 centimeters. We would use our stopwatch on our phones to calculate the time taken. We would do the same with the faster buggy. Once we did that, we would find that the slower buggy had a constant speed of 18.58 cm/s We got that by taking the distance the buggy traveled, 100 cm, and divided it by the time it took the buggy to get to the end of the 100 cm. As seen on the white board at the end of the post, it took the slower buggy 5.38 seconds to go 100cm. Therefore we took the distance - 100cm and divided it by the time - 5.38 seconds. We did the same thing with the faster buggy which went 100 cm in 2.5 seconds. Therefore we did 100cm/2.5 seconds and found that that buggy would go 40 centimeters in one second.   how did you get that?  what was your time and how did you calculate the speed?  and the constant speed of the faster buggy was calculated as 40 cm/s. We were given that the distance from each buggy would be 140 cm apart. After that we would graph both y=mx+b and find where on the graph the two lines would meet. The x value would then equal at what time in seconds the two would meet and the y value of the intercept would be where on the meter stick they would meet. good

can't see the picture for some reason?? try to fix these....



This would mean that the formula for the fast buggy would be moving at 40 cm per second and would be starting at a position of 0 cm. This would mean that to reach 100 cm would take this buggy 2.5 seconds. However, the end point would be 180 cm. This buggy would be starting at 0cm and moving in a positive direction, and since the opposite buggy is moving in a negative direction towards this buggy, they would meet at a certain point. confusing.....This does not show the intersection of the two points but gives the constant speed of the buggy. The formula being Position = (40 cm/s)time + 0



This would mean that the formula for the slow buggy would be moving at 18.58 cm per second and would be starting at a position of 140 cm. The starting position of the slower buggy would be 180 cm because it is starting on the opposite side of the meter sticks. Therefore, as opposed to the other buggy which starts at 0cm, this buggy would begin in the opposite direction, moving in a negative direction. is it 180 or 140????This would mean that to reach 100 cm, it would take a little less that 4 seconds. This graph does not show and intersection either however the formula being position = (18.57 cm/s)time + 180cm units...?



The graph above shows exactly where the two would intersect, at the point of (3.07,122.91). This would mean that if the buggies were started at the exact same time on either side of 140 cm, they would then intersect at 3.07 seconds and at 122.91 cm. This would mean that the fast buggy would have to travel a full 122.91 centimeters to intersect with the relatively slower constant speed of the other buggy that would only move 57.09 centimeters over the course of 3.07 seconds.good

After testing our theory of whether the buggies would meet at that exact point we found that the buggies did meet at the relative point within the same amount of time. As you can see from the photo below, they met at about 123 cm within the time of 3.71 seconds. This shows that our calculations we very close however our time was a bit off. To improve next time, we can test the constant speed of the buggies multiple times to have a more precise constant speed and therefore more accurate calculation.

Buggy Lab

Members: Patrick Coh, Sabrina Espiritu, Jon Abello
Group #
Prelab observations
Buggy had a constant speed
Went forward not backward, turned around
Lights up and is red
The wheels are black
Flowers, noise
Antenna
Has batteries

Measure position - place on number line

Objective: ???
Your Plan:
Gather two measuring sticks and place them next to each other. After, tape down 5 different lengths on the meter sticks each separated by 40 cm each. Place the buggy at the beginning of the first yard stick and measure how long it takes to get from the start point to each length on the stick. After repeat the same process but this time, add a 500 g weight to the car. Securely fasten the weight with tape to ensure the safety of the buggy's heavy passenger funny!. Write down the data and record the results.

data tables??

force origin to (0,0)

VM: As the time (sec) increased, the position (cm) increased proportionally
MM: Position = (45cm/sec)time - 10cm
Slope: For every second, the buggy increased forward position by 45 cm.
Y-int: when time is 0 seconds the position is -10 cm

Trial 2:
We recorded the amount of time it took for the buggy to travel to a certain position with 500g of weight added
this analysis does not match your graph...  did you put numbers on wrong axes?
VM: as time increased the position increased proportionally
MM: position = (42cm/sec) time - 2cm
Slope: for every second, the buggy's position increased 42 cm
Y-int: when the time is 0 seconds, the position is -2cm
this graph analysis doesn;t match this graph?

and why is this STILL not done!?!?!  I waited an entire week for this after Kairos!  This is not going to cut it. 

Earth-Moon Lab

First, we had to measure both the moon and the Earth before moving on to anything else. Not being able to use rulers, we used the next best thing: our phones and then checking the internet to see how long our phones were. After finding out the Iphone 5 has a length of about 5 inches, we used that information to see how much the Earth's length was and the moon's length was. After using our phones to find the length of the model sizes, we converted the actual length of the Earth and moon to inches to make the units the same in our proportions. We then used the proportions to figure out what this enormous amount of inches was in relation to the size of our model Earth and Moon. Wanting to be exact, we measured my ipad and used that to measure the length between the Earth and Moon in inches.
This is the length we came up with (about 12.5 Feet):

Here is the work we did to calculate the length: