Friction Forces

Purpose:

In this lab, the main purpose to determine the static friction between the block and table top. To do so,  we need to get the block at the breaking point to sliding. We measured the static friction 4 different methods. Water cup, slope force sensor, force sensor pulling, and weighted mass. 

Lab Set Up:

Here we used a force sensor on a sloped surface. We let the block slide down from a certain length and measure the acceleration. 

Here we used the mass at the end and force sensor to measure the force of the block.  As the mass increases, the acceleration also increase. 

Another method we used is the water cup. We attached a water styrofoam cup to one end and tied the other end of the block. For the first block, we filled the cup slowly with water until the cup starts to slip. Then we measure the mass of the cup and record the weight. We repeat this process with 2, 3, and 4 blocks. 

This data table is for the water cup method.

The maximum static friction is the slope of the graph. Here the slope is 0.3649.

Force Sensor Pulling Method. As the block increase the average kinetic friction doubles. 

This is the slope of the ramp which we set up. 

Summary:

In this lab, we discover the many different ways to test and calculate static and kinetic friction. The most accurate is the force sensor method. To obtain the coefficient of friction, we must plug in the value in a chart and test a linear fit to find the slope.