Physics Circle home Student Login

Home›Chapters›Work, Energy and Power PYQs›Work by a Variable Force›Question 15

JEE Main 2020 (9 Jan, Shift 1) · Work by a Variable Force

Work by a Variable Force question from JEE Main 2020 (9 Jan, Shift 1)

Q15JEE Main 2020 · 9 JAN · SHIFT 1Difficult

Work by a Variable Force

Consider a force F⃗=−xi^+yj^\vec{F} = -x\hat{i} + y\hat{j}. The work done by this force in moving a particle from point A(1, 0) to B(0, 1) along the line segment is: (all quantities are in SI units)

Figure

Show answer and solution

Answer: (c)

  1. W=∫Fx dx+∫Fy dyW = \int F_x\,dx + \int F_y\,dy from A(1, 0) to B(0, 1).
  2. ∫10(−x) dx=12\int_1^0 (-x)\,dx = \frac{1}{2}
  3. ∫01y dy=12\int_0^1 y\,dy = \frac{1}{2}
  4. W=12+12=1 JW = \frac{1}{2} + \frac{1}{2} = 1\text{ J}, so the answer is (c).
Report a mistake

More questions on Work by a Variable Force