9/26 MS Physics update and homework due 10/3

Hi folks,

Today we put our newly discovered concept of speed to the test by having the students figure out, on their own, how to find the speed of a dart shot from a nerf dart gun.  It was a bit of a challenge but at the end everyone collected a nice set of data.  Turns out those little darts really go!

For homework this week please answer the following questions about today's class and lab.

1.  What is the definition of precision?

2.  What is the definition of accuracy?

3.  Draw a picture that illustrates precision.

4.  Draw a picture that illustrates accuracy.

5.  Draw a picture that illustrates accuracy AND precision.

6.  Draw a picture the illustrates poor accuracy and poor precision.

Answer these questions based on today's lab.

1.  What two things did you have to measure to find the speed of the darts?

2.  What 3 things introduced the greatest amount of error into your data.  In other words, where was it the most difficult to be accurate?  If you had to do this experiment again, what would you do differently to get more accurate data.

3.  Take a look at the data table that I've included.  Answer the following questions based on the data.

a.  One group seemed to get consistently higher numbers than the others.  Why do you think that is?

b.  One group seemed to get consistently lower numbers than the others.  Why do you think that is?

c.  If we leave out the data from the ODG group (which is quite a bit different than everyone else) the average is 30 mph.  With that in mind, which group's data seems to be the most accurate?

d.  Which group's set of data is the most precise?

e.  The data from ISP seems to be quite a bit higher than the rest of the groups even though they were using the same type of dart gun.   Create 2 testable hypotheses why this might be so.  What experiments could you do to test your hypotheses?