Friction Gravity Lab

Brandon Ebba

Physics 1,2 - BLK. 3

Partners: Maxwell, Jacky

Friction Gravity Lab

Friction is the interaction between two parallel surfaces. In this case, Friction is a result of the block and the table surfaces rubbing against each other. The block has two surfaces, one bumpy and one with circles. Not only is there two different surfaces to measure, the block will have a variety of weights on it to test the amount of friction is a result of these factors. We are to drag this block with weights on it to determine the amount of friction force happening while it's moving. 

Pre - Lab Notes:

What factors influence Ff?

• Ground
• Angle
• Strength of people
• Characteristics of surface
• Mass

Fn (N) = m * 9.81

g=9.81

Ff=M * Fn

Question: How much friction is there on the block from the table

Purpose:

By doing this experiment, we will discover the Friction Force that's happening between the two surfaces. We are given the block with two surfaces, a variety of weights, and a table. With the spring scale we shall drag the block with weights and stay vigilant of the force it takes to drag it and record the data. The Friction Force (Ff) is a result of the two surfaces rubbing against each other. In this case we will take the mass (kg) multiply that by 9.81 to get the Normal Force (Fn), and drag it across the table to determine it's Frictional Force. This lab will determine what really happens to the Frictional Force when weights are added to it.

Prediction:

Our prediction is that that the bumpy surface will have more a Frictional Force (Ff) due to it's sticky surface compare to the circle surface. Not only will the bumpy surface will have more of a Frictional Force, when added weights the Frictional Force will be greater. In the wake of this, as the Mass (Kg) increases so does the Frictional Force (Ff).

Apparatus (Materials):

• Spring scale
• Weights (variety)
• Block
• Bumpy side
• Circle side

Procedure:

1. Gather all materials.
2. Connect spring scale to block.
3. Determine it's Mass (Kg) by retrieving the Newtons from the block with the spring scale, and convert using M * 9.81.
4. Place block on the table, Bumpy Side down.
5. Use meter stick to help guide you:pulling block @ a constant velocity.
6. While pulling block @ a constant velocity, read the value of the spring scale.
7. Record the value you observed and record it on to your data table.
8. Place weights on to the block. (90g, 100g, 110g, 140g, 190g)
9. Flip the block and proceed to re-do the lab from Step 3 for the circle side.
10. Should have 5 trials total for both sides of the block.

Note: All mass data, should be recorded in measurements of kg. Thank you.

Data Collection:

VM: As the Mass increases, the frictional force increases proportionally

MM:y = 1.56x - 0.411

Slope:1.56

Y-Intercept:-0.411

VM: As Mass increases, the frictional force increases proportionally.

MM:y = 0.0323x - 0.21

Slope: 0.21

Y-Intercept: -0.791

Data Analysis:
As you can see as the Frictional Force (Ff) increases when we increase the Mass (Kg). I can prove that because if you read the masses from top to bottom, then look at the Frictional Forces from top to bottom, you can see that it does increase in force when the mass does. I can say that because judging from the graphs themselves, they all POSITIVE slopes. Positive slopes indicate when one variable increases so does the other variable. In this case when we increased the mass, the frictional force did also. The bumpier side had a high frictional force due to its grippy surface, while the circle side had less grip whom had less fictional force. You would expect most Y-Intercepts to start at zero, but since the measurements didn't start at zero the Y-intercepts start a little higher. We started with measuring the block alone, which gave us that Y-intercept.

Conclusion:

This Lab is to be conducted as a further investigation of what happens when we add more mass to the block that we are experimenting with. We are given a spring scale where we will attach the block and drag across the table, but after each trial we increase the mass. We predicted that when the mass (kg) increases, the Frictional force (Ff) increase proportionally. Judging from the data we collected and the graphs that we made as a result, it seems that our prediction was correct. Since if you look at the graphs that the slopes are positive. Positive in this case means that when we increased the mass, the frictional force did so as well. The only variable that exchanged throughout the lab was the mass, which increased the results in later trials. Compared to other groups analysis and graphs, ours is fairly similar in a way that everyone had the same idea. The idea that increasing the main variable, which is Mass and Normal Force also increases the Frictional Force. Minor errors here and there of course would occur. The surfaces were totally different, the bumpy side had a grippy surface compared to the circles who had a carpet like material. In this lab both sides should have the same material or else it will toss the data a little more off. We didn't necessarily kept a constant velocity, so human error is somewhere in this. Y-Intercepts are suppose to be zero due to the fact that the normal force and gravitational force are equivalent when no other force is occurring on the objects themselves. So forth, small errors like these did not significantly change our data, but it is something to consider when doing this lab. This lab basically is taken to account to prove that a smile variable change will increase the dependent variable, however, all small errors should be taken into account so that the numbers are little more accurate.