1.

A body of mass 0.8 kg has intial velocity `(3hati-4hatj) ms^(-1)` and final velocity `(-6hatj+2hatk) ms^(-1)`. Find change in kinetic energy of the body?

Answer» Change in kinetic energy
`DeltaKE=(1)/(2)mv_(f)^(2)-(1)/(2)mv_(i)^(2)`
where, `v_(f)=sqrt(6^(2)+4^(2))=sqrt(40)`
and `v_(i)=sqrt(3^(2)+4^(2))=sqrt(25)`
`(1)/(2)xx0.8[sqrt(40))^(2)-(sqrt(25)^(2))]`
`=0.4[40-25]=0.4(15)=6 J`


Discussion

No Comment Found

Related InterviewSolutions