Question

The work done by a force F =(-6
${x}^{2}$
î) N in displacing a particle from x= 4 mto x=-2 m is
(A)-240 J
(B) 360 J
(C) 420 J
(D) will depend upon the path​

Answer 1

Answer:

Work done is 144 J.

Explanation:

Given,

The work done by a force F =(-6 x² î) N in displacing a particle from x= 4 m to x=-2 m.

Solution:

We know,

Work done = F. dx

or, ∫ dW = ∫ F.dx cos 0°

W = ∫₄⁻² 6x² dx

or, W = [  6x³ / 3 ]₄⁻²

or, W = 2 [4³ - (-2)³ ]

or, W = 2 [ 64 + 8]

or, W = 2 * 72

or, W = 144 J

None of the option is 144 J. So either the options are incorrect or question is incorret.