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In addition, the script saves the current values of t and h in oldT and oldH to be used to estimate the velocity during the next iteration of the while loop.

Finally, the time value is increased by the value stored in the variable named tInc , and control goes back to the top of the loop where the current value of height is tested to determine if it has become negative(meaning that the arrow has hit the ground).

Acceleration of gravity exercise #1

To repeat the earlier definition, acceleration is the rate of change of velocity.

You learned earlier that velocity is the rate of change of position. Then you learned that we can estimate the velocity of a moving object at a point in timeby determining the slope of a curve that plots the position of the object versus time at that particular point in time.

Positive and negative velocity

Positive slopes indicate positive velocity and negative slopes indicate negative velocity. In the case of ourarrow, the velocity went to zero and switched from positive to negative at the point where the arrow reached its maximum height and began to fall back towardthe earth. In a math class, that point would likely be referred to as an inflection point on the curve of position versus time.

Estimating acceleration

We can extend that procedure to estimate the acceleration of a moving object at a point in time by determining the slope of acurve that plots the velocity of the object versus time at that particular point in time. Positive slopes indicate positive acceleration and negative slopesindicate negative acceleration.

Estimate some velocity values graphically

If you have the velocity curve from Figure 6 plotted on your graph board, I recommend that you estimate and record the slope and hence the acceleration at afew points. That should be easy to do in this case, because the velocity curve should be a straight line with a negative slope.

A constant acceleration value

If the velocity curve is a straight line with a negative slope, and if the acceleration at any point in time is equal to the slope of the velocity curve, thatmeans that the acceleration has a constant negative value throughout the time interval of interest. In fact, you should find that the value of theacceleration is approximately -32.2 feet/second^2, which is known as the acceleration of gravity .

Create a script

Please copy the code from Listing 3 into an html file and open that file in your browser.

Listing 3 . Acceleration of gravity exercise #1.
<!---------------- File JavaScript99.html ---------------------><html><body><script language="JavaScript1.3">document.write("Start Script</br>"); //Declare and initialize constantsvar g = -32.2;//acceleration of gravity in ft/(sec*sec) var v0 = 100;//initial velocity in ft/secvar h0 = 6;//initial height in feet var tInc = 0.25;//calculation interval in seconds//Declare and initialize working variables var t = .0001;//current time in secondsvar h = h0;//current height in feet var v = 0;//current velocity in feet/secvar a = 0;//current acceleration in feet/(sec*sec) var oldT = 0;//previous time in secondsvar delT = 0;//change in time in seconds var oldH = h0;//previous height in feetvar delH = 0;//change in height in feet var oldV = 0;//previous velocity in feet/secvar delV = 0;//change in velocity in feet/sec //The following variable is used to insert spaces in// the output display. var sp = "&nbsp;&nbsp;"; //Compute and display various values for as long as the// height of the projectile is above the ground. while(h>0){ //This is the general equation for the height of a// projectile under the influence of gravity in a // vacuum.h = h0 + v0*t +0.5*g*t*t; //Compute and save the time interval since the// previous estimate of height, etc. delT = t-oldT;oldT = t;//Save the current time for the next iteration. //Estimate the velocity based on the change in// height since the previous estimate. delH = h-oldH;v = delH/delT;//compute velocity oldH = h;//Save the current height for the next iteration.//Estimate the acceleration based on the change in // velocity once the data pipeline is full.delV = v - oldV; oldV = v;//Save the current velocity for the next iteration.if(t>2*tInc){ a = delV/delT;//compute acceleration}//end if //Display the information for this iterationdocument.write( "t = " + t.toFixed(2) + " sec" + sp +" h = " + h.toFixed(0) + " ft" + sp + " v = " + v.toFixed(2) + " ft/sec" + sp +" a = " + a.toFixed(2) + " ft/(sec*sec)" + "</br>"); //Increment the time for the next iteration.t = t + tInc; }//end while loopdocument.write("End Script");</script></body></html>

Questions & Answers

a perfect square v²+2v+_
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algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
y=10×
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if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
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rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
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Differences Between Laspeyres and Paasche Indices
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No. 7x -4y is simplified from 4x + (3y + 3x) -7y
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is it 3×y ?
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J, combine like terms 7x-4y
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im not good at math so would this help me
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f(x)= 2|x+5| find f(-6)
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f(n)= 2n + 1
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Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
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. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
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preparation of nanomaterial
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Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
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Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
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the Beer law works very well for dilute solutions but fails for very high concentrations. why?
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Source:  OpenStax, Accessible physics concepts for blind students. OpenStax CNX. Oct 02, 2015 Download for free at https://legacy.cnx.org/content/col11294/1.36
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