Purpose: to Get Acquainted with the CPO Lab Timer

Lab 1.1 and 2.1

Lab 1.1:

Purpose: To get acquainted with the CPO lab timer.

Materials:

·  1 box containing: CPO timer, 2 Photogates, 2 cords, 1 AC adapter

·  Lab manual for the group

Procedures:

1)  On pages 2-3 of the lab manual, “Using the photogates”

a)  Answer Section 2 question 4a, be specific

b)  Answer Section 2 question 4b (the first two sentences), be specific

2)  Pg. 3 of the lab manual, “Using the timer with two photogates”

Ø  Answer Section 3 questions a through e – be and be as specific as possible.

Lab 2.1

Purpose: To practice calculating speed, interpolating from graphed data, and calculating percent error

Materials:

§  The box and CPO timers from the previous lab

§  Lab manual for the group

§  1 piece of graph paper for each group member

§  1 wooden car with wingnut

§  At least 1 calculator per group

§  1 Photogate & cord

§  1 Ramp

§  1 Physics Stand

§  2 metal weights

Procedures:

1)  Set up the ramp at the hole of your choice (must be at least at hole #2)

2)  Place 2 weights on your car

3)  Set Photogate A at the first position indicated in the data table

4)  Set the timer to Interval, with the A light on

5)  Release the car and record the time through photogate A (recall that we record ALL of the digits provided by digital equipment)

6)  Calculate the speed of the car as it passed through the photogate

§  Using only 1 photogate, the Speed of the Car = 5 cm / time through Photogate A

7)  From page 11 in the lab manual, and the section “Graphing and analyzing your results”

§  Answer question a, be specific

§  Graph the speed of the car versus the position of Photogate A (since these are different events, use a scatterplot with a “best-fit line” for your data)

§  Answer question c, be specific

8) After you have made your line graph, answer 3a – e from the “Using your graph to predict the speed of the car” section on page 11 of the lab manual (Record this data in the attached data tables)

9) Using the data from the previous step, answer 4 a-c from the “Calculating Percent Error” section on page 11 of the lab manual and enter the calculations in the attached data tables.

Data for Lab 2.1:

Position of Photogate A from the top of the ramp (cm) / Time through Photogate A (seconds) / Distance traveled by car (cm) / Speed of the car (cm/sec)
15 / 5
30 / 5
45 / 5
60 / 5
75 / 5

Data Table for Lab 2.1 Steps 8 and 9:

The Position from the top of the ramp that the group did not previously measure
(cm) / Estimated Speed at the new position (cm/sec) / Distance traveled by the car
(cm) / Actual time recorded at the new position (seconds) / Actual Speed of the car at the new position (cm/sec) / Percent Error (%) / Percent Correct (%)
5