Warm-up  How much force would be needed to move a dog that is 65kg at an acceleration of 2 m/s 2 ? (Find the weight!)  Find the Weight for the following:  m = 25kg  m = 101 kg  m = 12.5 kg  m = 850 kg

Can a penny dropped from the top of the Empire State Building have enough energy to crack the concrete sidewalk? What would you need to know to answer this question? What other forces could influence the outcome ?

Investigating Falling Objects Drop the ball onto the motion detector from 4 different heights. What is the “change” that is being measured? Purpose: How does an object’s drop height (and its GPE) affect its speed as it falls?

What patterns did you observe in the data?

GPE = mass x gravity x height = mgh  So can the penny crack concrete if it is dropped from the top of the Empire State Building?  As the GPE transforms into KE, the speed at which the penny strikes the sidewalk should be about 200 miles per hour!

Mythbusters “Death By Falling Penny 

A discrepancy in the data?  When tested, the falling speed of the penny was only about 65 miles per hour.  What happened?  Where did the energy go?

WORK UNIT:______ GPE UNIT:______ FORCE UNIT_____ Complete in your Journal: Left Side Answer the following word problems Question #1: A 2.8 kg textQuestion #2: a 84 kg student is book is on a table that is standing on top of bleacher that 3 meters highare 12 meters high Mass =Mass =Gravity = Height =_________ Height =___________ GPE = GPE =

Air Resistance Lab  Did Air resistance play a role in yesterdays lab?  Let’s Find out!  You will be working in same groups as yesterday  Assign Roles! Recorder Dropper Measurer Manager

 Mass of 1 Coffee Filter is 1.6 g as you add a coffee filter times by the number you have  Calculating Terminal Velocity- 1 divided by the speed you calculated  Averages: add the 7 trials together and divide by 7 Air Resistance Lab

GPE Lab Report- Due Tuesday  Introduction-  Hypothesis: If the distance doubles then the speed should double as well  Purpose: To determine what affects an object’s GPE  Explain the purpose as well- give some details  Procedure- tell me what we did in BOTH labs  Data- Give me data from BOTH labs (the ball lab you should have your data in your questions that you answered)  Analysis- Give me two graphs one from Each LAB- explain what the data says  Conclusion- How does height and air resistance affect speed as something falls? What did you learn? Tell me about GPE