Peer Review Do they have a complete prelab (hypothesis & graph sketch), methods, & materials? Is there a labeled data table? Are example calculations for v & a shown? Does their graph have a title, labeled axis, & trendline? Is there hypothesis restated & evaluated? Is there data (v & a) that supports their evaluation? If they disproved their hypothesis is there an alternate hypothesis? Reason for errors in the data are given and specific points are used to illustrate the affect the error had on data. The above information includes multiple data points, describes the trend in data (as time does this position/velocity does this), unusual data points are commented on (most likely in error discussion).

9/26 Free Fall

Free Fall Free fall is an object that is only under the influence of gravity A free falling object accelerates at 9.8 m/s/s downward, g a=Δv/t, a=-9.8m/s/s Quiz on 80

Free Fall Graphs A curved position-time graph represents an accelerating object. An object in free falls starts with a slow initial velocity and ends with a large downward velocity A velocity-time graph going away from the x axis represents an object gaining speed (this case in the negative direction)

Free Fall Calculations To calculate final velocity (vf): vf=g*t To calculate distance fallen (d): d=1/2*g*t2 Quiz on 86

Misconception Doesn’t an object with more mass free fall faster than an object with less mass? NO! Free falling objects don’t take into account additional forces (such as air resistance) only the force of gravity. https://www.youtube.com/watch?v=E43-CfukEgs