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Video Analysis LabAnalyzing the motion of an object in freefall6153150114300Experiment: An object is dropped from rest as shown in this video. Gather ten data points about the motion of an object during freefall using the tools in the video.Before you BeginWhat does it mean when an object is in freefall?When the only force acting on the object is gravityUsing the VideoClick this link to access the video we’ll be using to analyze an object in freefall. Watch the video once to see the little pink ball fall in freefall.Why do some physics experiments (like this one) need to make the use of a video that can be advanced frame by frame?So you can measure the position at a more accurate time.4533900238125Use the tool shown at the bottom of the video to advance the video frame by frame.Stop and Think QuestionWhat information in the video tells us that the downward direction is defined as negative?The object starts at the top, and at the bottom, and the numbers on the ruler get smaller.In order to use the equations of motion to analyze the ball in freefall we have to begin looking at the situation when the ball is in the air.What is the initial velocity of the pink ball when it is in the air, after the person releases the ball but before gravity has had any time to act on the ball?Justify your answer with information from the ‘Experiment’ description at the top of this document.0 m/s is the initial velocity because when the ball is released, the ball is still at the smae spot and not moving before gravity has any time to act.Why can’t you find the final velocity by dividing the total displacement by the total time?Because the the object accelearates and does not fall at a constant velocityData: Initial Position, yi(m)Initial Velocity, vi (m/s)2.000Gather these pieces of data from the video.Use the equations of motion to calculate these values.Final Position, yf(m)Time, t(s)Total Displacement, ?y(m)Final Velocity, vf(m/s)Acceleration, a (m/s/s)2.00000.0000.0001.910.1330.09-1.353-10.1761.730.2330.27-2.318-9.9471.640.2670.36-2.697-10.1001.310.3670.59-3.760-10.2461.040.4330.96-4.434-10.2410.890.4671.11-4.754-10.1790.560.5331.44-5.403-10.1380.190.6001.81-6.033-10.0560.000.6332.00-6.319-9.983Analysis: Create a position vs. time graph of your data. Include a title, axes labels with units, and a trendline that best fits the data.Paste the graph in the space below: How does your position vs. time graph demonstrate that the ball has a constant acceleration? Throughout the whole time period, the ball’s acceleration at the various points is very close to -10m/s/s. The graph is also a quadratic function which means that acceleration is constantUsing only the equation for your best fit line on the position vs. time graph, determine the acceleration of the pink ball in freefall.Hint: ?y = vi?t + 12a?t2 -2.00m = (0m/s/s)(0.633s) + ½ (a)(0.633s)2((-2.00m)-(0m/s/s)(0.633s)) / ( ½(0.633s)2) = aa = -9.983m/s/sCreate a velocity vs. time graph of your data. Include a title, axes labels with units, and a trendline that best fits the data.Paste the graph in the space below: How does your velocity vs. time graph demonstrate that the ball has a constant acceleration? The line of the velocity vs time graph is linear, which also means it has a constant slope. The slope of velocity vs time graph is equal to the acceleration. So because the slope is constant, the acceleration is constant.Using only the equation for your best fit line on the velocityvs. time graph, determine the acceleration of the pink ball in freefall.Hint: vf = vi +a?t -6.319 = (0 m/s) + a (0.633s)(-6.319 m/s) / (0.663s) = -9.98m/s Create an acceleration vs. time graph of your data. Include a title, axes labels with units, and a trendline that best fits the data.Scale your acceleration vs. time graph so that the vertical axis shows values from -15 m/s/s to +15 m/s/s.Paste the graph in the space below: How does your acceleration vs. time graph demonstrate that the ball has a constant acceleration? After 0, seconds when the ball is not accelerating, the ball maintains a constant acceleration of about -10m/s/s. This is shown in the graph because there is a flat line at y = -10, which means acceleration remains constantUsing only the equation for your best fit line on the acceleration vs. time graph, determine the acceleration of the pink ball in freefall.The line of best fit for this graph is essentially a flat line with the equation ofy = -10, with a slope of 0. Because of the slope of 0, the acceleration remains the same. So the acceleration is -10 m/s2If the pink ball was dropped from 4.0 m off the ground, what would its velocity be right before it hits the ground?vf2 = vi2 +2a?x ((0 m/s)2 + 2(-10 m/s2)(-4.0m))1/2 = 8.94 m/s
