All Students: Slopes and other lab problems

1) A slope of a linear graph is a single number! It is found by:

drawing the best fit line through the data
then using this line find the numerator by the subtracting the vertical coordinate of initial point on the line from the vertical coordinate of the final point.

Then find the denominator by subtracting the horizontal coordinate of the intial point from the horizontal coordinate of the final point.

When you divide the numerator by the denominator you have the slope one single value.

It is this single value you should use in the equations described in my lab instructions to you and in the post of 2/18 on labs

2) Focus on the purpose. We are usually trying to prove somethingwe derived or developed from observations is correct. Examples: Does a = F/m?; does a centripetal = omega squared r?; do relative velocities add? ; does omega really equal square root ( k/m)

For the Ferryman lab: purpose was to show that relative velocities of A to B and B to C are added to find velocity of A relative to C. In this lab, A to B was boat relative to ( as seen from the pooint of view of the) river, B to C was water relative to shore. Most of you focused on the details and missed the purpose.