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

`17//s`

Explanation

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))`