Drops+on+a+Penny


 * Drops on a Penny **

Water has a tendency to act as if it has a very thin net stretched over its surface. This tendency is called surface tension. Surface tension is caused by the polar nature of the water molecule.
 * Introduction: **

 The polar charges are caused by electron sharing of the atoms of the molecule. This sharing causes areas of the molecules to become positively and negatively charged. The charged areas are called poles. Opposite charges attract causing the pole on one molecule to be attracted and "cling" to an oppositely charged pole of another molecule.

This cling, or adhesion, of molecules forms the "net" called surface tension. As water piles up on a penny, it creates a dome-like shape. It will even bulge over the edge of the penny. The "net" of surface tension keeps the water from spilling off. Surface tension will support this bulging dome until the water piles up so high that the force of gravity on the water becomes greater than the strength of the net and it is ripped open as the polar bonds


 * Standards: **

CCSS.Math.Content.8.SP.A.1 Construct and interpret scatter plots for bivariate measurement data to investigate patterns of association between two quantities. Describe patterns such as clustering, outliers, positive or negative association, linear association, and nonlinear association.

CCSS.Math.Content.8.SP.A.2 Know that straight lines are widely used to model relationships between two quantitative variables. For scatter plots that suggest a linear association, informally fit a straight line, and informally assess the model fit by judging the closeness of the data points to the line.


 * Learning Objectives: **


 * I will be able to make a prediction of how many drops of water a penny can hold on its surface (heads or tails).
 * I will be able to create a graph based on my data collected and find the mean, median and mode.
 * I will be able predict how many drops a quarter can hold based on my data collection and graph.

Students work in pairs
 * Group Arrangements: **

Tools:
 * Dixie cups
 * <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">Water
 * <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">Eye Dropper
 * <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">Paper towels
 * <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">Pennies


 * Questions: **
 * What will happen if we pour drops of water on the surface of a penny?
 * How many drops do you think it can hold?
 * Why does water act in such a way?
 * Based on your data collected how many drops do you think a quarter can hold?
 * What was your mean, median and mode for your three trials with a penny?

<span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">1. Guess how many drops of water a Heads-Up penny will hold. <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">2. Count how many drops it will actually hold. <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">3. Record your data. <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">Use this data to create a graph. <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">
 * <span style="color: #ff0000; font-family: 'Times New Roman',Times,serif; font-size: 120%;">Procedure: **
 * <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">COLLECT THE DATA
 * <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">GRAPH THE DATA
 * 1) <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">1. Create a Stem-and-Leaf plot of the class data.
 * <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;"> ANALYZE THE DATA
 * 1) <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">1. Use the data to calculate the mean, median, mode and range.
 * <span style="color: #ff0000; font-family: 'Times New Roman',Times,serif; font-size: 120%;">Assessment: **
 * <span style="font-family: 'Times New Roman',Times,serif; font-size: 120%;">Predict how many drops of water a Tails-Up penny will hold and check your prediction. Draw a graph and compare to the data for the Heads-Up penny.