Question

A particle moves from position 3i+2j+6k to 14i+17j-9k due to a uniform force of 4i+j+3k n find the workndone if yhe displacent in metres

Answer 1

Work done is given by scalar (or dot) product of force and displacement vectors.

Here, displacement will be given as d = r' -r = [( 14i + 13j - 9k ) - ( 2i +j - 4k )] = ( 12i + 12j - 5k) m

Force , F = (4i +j +3k) N

so, the work done, W = F.d = (4i +j + 3k).(12i + 12j - 5k) = 4 × 12 + 1 × 12 + 3 × (-5) = 45 J