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InterviewSolution
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A bolck of mass `10 kg` is moving in x-direction with a constant speed of `10 m//s`. it is subjected to a retardeng force `F=-0.1 x J//m`. During its travel from `x =20m` to `x =30 m`. Its final kinetic energy will be . |
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Answer» According to work-energy theorem, work done =change in kinetic energy of the vehicle `:. W=K_(f)-K_(i) orF.dx=K_(f)-(1)/(2)mv_(i)^(2)` or `F.dx=k_(f)-(1)/(2)xx10xx(10)^(2)or F.dx =k_(f)-500` or `int_(x=20)^(x=30)(-0.1)x dx=k_(f)-500` or `-0.1[(x^(2))/(2)]_(x=20)^(x=30)=K_(f)-500` or `-0.1[((30)^(2))/(2)-((20)^(2))/(2)]=K_(f)-500` or `K_(f)-500=-0.1(450-200)` or `K_(f)-500=-25` `:. K_(f)=500-25=475 J` |
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