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Old Dec 12th 2018, 10:33 AM   #1
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Acceleration

x=50-15t+t^2 and there are questions a)what is the first/initial coordinate b)what is the initial speed c)what is the Acceleration d)find velocity when t=3 m/sec e)find coordinate when t=3 m/sec f)find At what moment of time coordinate equals 0 g)Write the equation of velocity on time
so i should write this and its acceleration so we need formula X=Xo+Vot+at^2/2 right ?
so a)x=50 meters b)Vo=-15 m/sec c)a=2 m/sec^2 d)v=-9m/sec e)x=14 meters its like that right please help if u can :d and SORRY FOR MY BAD ENGLISH
and know on f)x=50-15t+t^2 and we should equal that to 0 right ? and it would be t^2-15t+50=0 but i get D=225-100=125 and is not it a problem ?
g)V=Vo+at
can you guys tell me if this is right if not help how should i do :d
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Old Dec 12th 2018, 12:19 PM   #2
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You have parts (a) through (e) done correctly. For (f), you are correct that you need to solve for t:

0 = 50-15t+t^2

What do you get for t? Hint - this is a quadratic equation, so you can either factor the equation or use the quadratic formula to solve for t. You will find that there are actually two solutions.

As for (g), you have the right equation, but I think they want you to include the actual values of the coefficients Vo and a.
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Old Dec 13th 2018, 09:16 AM   #3
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thank you for help
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