Notes from 8/29/13

T-Charts (cont.)  Check Units!  For given information (2), check that same quantities have the same unit (ex. time: s and min should be ALL seconds or minutes not both)

Bellwork (8/30/13)  What is the difference between quantity, variable and unit?  Answer: A quantity is the description or name The variable is the symbol for the quantity The unit is how it is measured

Variables in Experiments  Independent Variable: the one factor that is changed by the person doing the experiment  Dependent Variable: the factor which is measured or calculated in the experiment  Controlled Variable (constants): all the factors that stay the same in an experiment

Variables in Experiments  Independent variables answers the question "What do/did I change?"  Dependent variables answers the question "What do/did I record and calculate?"  Controlled variables answers the question "What do/did I keep the same?"

[Lab Title] Name Period # 8/29/12

Purpose:  To study the motion of an object traveling down a ramp.

Purpose: (Aside)  The component of gravity that acts along an incline plane is less then the full force of gravity that acts straight down – so the change of speed happens slower and is easier to measure.

Materials:  Ramp  Meter Stick  Stopwatch  Ball Bearing  3 Books

Procedures:  [Given on the lab table]

Procedures: 1.Place a metal ramp on top of one physics book and place another at the end of the track to stop the ball from rolling off the table. 2.Using the meter stick release the ball from m distances from the bottom of the ramp. Repeat every m until you get to the top of the ramp m. 3.Release the ball and use a stop watch to time how long it takes the ball to reach the end of the ramp. Take FOUR trial times for each distance and record it in your data table. 4.Add another book under the ramp and repeat steps 2 and 3.

Collecting Data  Be precise! (distance and time)  Releasing and side of the ramp  Stay with your group and on task, this is the only day for data collection  Return the ball bearing to Mr. Z.  Leave the lab as you found it  Return to your desks when finished collecting data

[Lab Day 2] 8/30/13

Calculations:  1. Calculate the average time for all of the distances. Show your work for 6 calculations  2. Calculate the average velocity for all the distances (in meters!). ***Use T-Charts for the first 6***

Graphs: (You will have two graphs total.) Use the whole graph with an appropriate scale Include titles and units Graph 1: Make a graph with time on the x- axis and distance on the y-axis. Graph 2: Make a graph with time on the x- axis and average velocity on the y-axis. *** Plot the data from the two data tables on the same graph ***

Conclusion: (6 sentence min. in paragraph form) Identify the independent, dependent and controlled variables. Explain your data. (use titles) –How was it collected? –Do you notice any trends? Explain your graphs. (use titles) –What are the shapes and slopes of the graphs? –What are the trends? Compare your graphs to the ones on p. 23 in the textbook. What were the sources of error in the lab?

Order of the lab  Title, Purpose and Materials  Calculations  Data  The graphs  Conclusion