Question

17.
A force F=-K(yi xj) where K is a positive constant, acts on a particle moving in the x-y plane.
Starting from the origin, the particle is taken along the positive x-axis to the point (a.) and then parallel
to the y-axis to the point (a, a). The total work done by the force F on the particle is
(A) -2Ka'
(B) 2Ka
(C)-KP
(D) Ка
​

Answer 1

Explanation:

We know that,

Work done=Force x displacement

For origin to (a,0), the total work done=W

=ai[-K(yi+xj)]=-Kay=0

For (a,0) to (a,a),the work done=W'

=(aj+ai-ai).[-K(yi+xj)]=-Kax=

So the total work done=W+W'=0-2k^2=-2k^2