What is speed at X = 6? ( Physics) Help

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1 Answer
Apr 18, 2018

#~~1.30" ms"^-1#

Explanation:

We make use of the work-energy theorem which states that the increase in kinetic energy of a particle is equal to the net work done on it. Since the work done can be geometrically represented by the are under the #F#-#x# curve, we see that the work done from #x=0# to #x = 6" m"# is given by

#W = 1/2times 3" N" times 5 " m"+3" N"times(6-5)" m"=8.5" J"#

The initial kinetic energy being negligible, the kinetic energy of the particle at #x=6" m"# is given by #8.5" J. Thus

#1/2mv^2 = 8.5" J" implies v = sqrt((2 times 8.5" J")/(10.0" Kg")) ~~1.30" ms"^-1 #