1.

An object is moving along a straight line path from P to Q under the action of a force `vec(F)=(4 hati-3hatj+hat2k)N`. If the co-ordinate of P and Q in meters are (3,2,-1) and (2,-1,4) respectively. Then the work done by the force isA. `-15 J`B. `+15 J`C. `1015 J`D. `(4hati-3hatj+2hatk)`

Answer» Correct Answer - B
`vec(PQ)=(2-3)hati+(-1-2) hatj(4-(-1))hatk`
`vec(F).vec(PQ)=-4+9+10=15 J`


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