Dylan chu akeelah and the bee

For each measurement setup described in this section, we will measure two forces. First, we will measure the force that we need to exert on a wooden block so it starts moving from a resting position. This force is related to the coefficient of static friction. The second force is the force that we need to exert on the wooden block to keep it moving. This force is related to the coefficient of dynamic friction.

Because the wooden blocks in your lab kit are too light to produce accurate results, we will augment their mass by adding an object of constant weight, for example a can of soda. The experimental setup can be seen in figure 1 below. You can use any other object that you may have around instead of the soda can.

Figure 1: Experimental Setup

We will perform two types of measurements:

· Force of Static Friction (Fs): Starting from the block at rest, pull from the spring scale until the block starts moving. Record this force.

· Force of Kinetic Friction (Fk): Starting from the block at rest, pull from the spring scale until the block starts moving and continue pulling until it moves at a constant speed. Record this force.

You should observe that Fk is lower than Fs. We will repeat these measurements using several materials as well as in different configurations for the wooden blocks.

https://lh4.googleusercontent.com/DsuNyW65EDqZM744uTnisRIZJXVaRqsuLLf18UWvjpFY5XcDg2GK3yiBidfpNupOH1Ub1_rd-2xJLg-Xo5PQ3-BlU6sYJUdEwbqA6LEYZqm2t0Wr4EdmR-w3dIQrSUczEXBh4fY Question 1

What is the mass of the system made of the wooden block and the soda can (or the other object that you are using)?

https://lh4.googleusercontent.com/DsuNyW65EDqZM744uTnisRIZJXVaRqsuLLf18UWvjpFY5XcDg2GK3yiBidfpNupOH1Ub1_rd-2xJLg-Xo5PQ3-BlU6sYJUdEwbqA6LEYZqm2t0Wr4EdmR-w3dIQrSUczEXBh4fY Question 2

Convert the mass measured in Question 1 to its weight in Newtons. This is the value of FN that will be used in the calculations for the tables.

SURFACES

Wood / Wood (larger surface)

For this case, we will use the larger surface of the wooden block as was shown in Figure 1. Measure Fs and Fk as indicated in Section 3.1. Run 5 trials, completing Table 1 below.

https://lh4.googleusercontent.com/q3P2TznNbI-NvEOxRlx1MPFCtkYgTblwAdINlv9Y2bfDA_GZmLR9XwK_glIN-12QBp7EolK54ikqo_i7t6HvjSxvQu6IMgh5n3cwQGyUjmsxtsVe_CO85aUGZa30FqKg1kRL5Fs

Wood / Wood (smaller surface)

For this section, turn the wooden block on its side as shown in Figure 2 and repeat the experiment, completing Table 2.

https://lh6.googleusercontent.com/X8h4vQ4iMH4AP_rjEMFXNPFNG7_iWeght1GzCGDy-lrjNIzfPMRZ21x7SMuZTpg-5xYMTFppCrBoi4G7X8PXebsP15L7Z0lL-6hvgBSiLHbrJF3rfdhGOHKbf6H-n0ZXh_m_6YU

Figure 2: Wooden block on its side (courtesy of Chad Saunders, TESU student)

https://lh4.googleusercontent.com/IVwo7mH1eUsCM0ZmcuoUDqTSo0RFiOGDJ08SKjXcBU6rTlocoeOtSr29UQkiXPdXyxffqKV7gjaDJyi6LIDcGDUFFDFj5tYvd6RDdzAE6glX0uvHMuT2H9pPgT3KyJEF7rKETZg

Wood / Glass

For this section, use the glass surface of your wooden block to repeat the measurements and complete Table 3.

https://lh5.googleusercontent.com/BV7Iw1WjrudqPKObCPqqEYzvEqhvHlEPSbzOy2ixNGkSfQirpPWzcx70080k-nGd4CXzqnBiamIBvtBbku0KV61ee-fg5QaxsHZvM3MOoobFgCtT2EGTvsnropJ7RaHtcoqKaDs

Other surfaces

Repeat the measurements using other surfaces (for example, Wood / Sandpaper, Wood / Carpet, Glass / Carpet, etc.) When completing Table 4 below, make sure that you indicate the surfaces you used.

https://lh3.googleusercontent.com/OXsJnOoipVW0i7fOtO0xbN6o1CFpF7qUtG4VKNO_FztzW1axdt-VViC3D9rL1oVPCiNmJh886duXbfb4P-TubpDYPZYuULIucF5xQo5KCbN368iCedvPD-UqRYvtu6AG6MWGVlI

ANALYSIS OF RESULTS

https://lh4.googleusercontent.com/DsuNyW65EDqZM744uTnisRIZJXVaRqsuLLf18UWvjpFY5XcDg2GK3yiBidfpNupOH1Ub1_rd-2xJLg-Xo5PQ3-BlU6sYJUdEwbqA6LEYZqm2t0Wr4EdmR-w3dIQrSUczEXBh4fY QUESTION 3

Study the results from Table 1 and Table 2. What can you conclude about these results?

https://lh4.googleusercontent.com/DsuNyW65EDqZM744uTnisRIZJXVaRqsuLLf18UWvjpFY5XcDg2GK3yiBidfpNupOH1Ub1_rd-2xJLg-Xo5PQ3-BlU6sYJUdEwbqA6LEYZqm2t0Wr4EdmR-w3dIQrSUczEXBh4fY QUESTION 4