A body of 5 kg mass is raised vertically to a height of 10 m by a force of 120 N. Find the final velocity of the body using two methods: Newton's second law and the law of conservation of energy. The initial speed is zero.

A body of 5 kg mass is raised vertically to a height of 10 m by a forc

1.	A body of 5 kg mass is raised vertically to a height of 10 m by a force of 120 N. Find the final velocity of the body using two methods: Newton's second law and the law of conservation of energy. The initial speed is zero.
Answer» Solution :According to Newton.s second law `a=F/m-g,v = sqrt(2ah)=sqrt(2h(F/m-g))` (b) According to the law of conservation of energy the work per FORMED by a FORCE is equal to the change in energy `A = DeltaU+K , "or " Fh = MGH +(mv^2)/2` HENCE `v=sqrt(2h(f/m-g))`

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A body of 5 kg mass is raised vertically to a height of 10 m by a force of 120 N. Find the final velocity of the body using two methods: Newton's second law and the law of conservation of energy. The initial speed is zero.

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