Question

The gravitational field in a region is given by $\bar{E}=(4i+j)N/kg.$ Workdone this field is zero when a particle is moved along the line

• A. y+4 x=2
• B. 4 y + x = 6
• C. x + y = 5
• D. all of these

Answer 1

Answer: (A)

y+4 x=2

Answer 2

Workdone will be zero when displacement is perpendicular to the to .The told makes an angle $\theta_1 = \tan^{-1} \left(\frac{1}{4} \right)$ with positive x-axis. The line y + 4x = 2 makes an angle $\theta_2 = \tan^{-1} (-4)$ with positive x-axis