Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Work Power Energy

Question:

A force \(\vec{F} = (3xy - 5z)\hat{j} + 4z\hat{k}\) is applied on a particle. The work done by the force when the particle moves from point (0, 0, 0) to point (2, 4, 0) as shown in figure is : 

Options:

\(\frac{144}{5}\)

\(\frac{208}{5}\)

\(192\)

\(\frac{192}{5}\)

Correct Answer:

\(\frac{192}{5}\)

Explanation:

The z-component of the force and the x-component of displacement are ineffective here.

\(dW = F_y.dy = 3xy.dy\)

  \(= 6 x^4. dx\)

Integrating : \(\int_0^W dW = \int_0^2 6 x^4. dx\)

\(W = \frac{6}{5}x^5\)

\(W = \frac{6}{5}*2^5\)

\(W = \frac{192}{5}\)