The GATE Grind

GATE 2019 MT – Question 48

Engineering Mathematics · Calculus and vector calculus · 2 marks · Numerical answer

Find the work done by $\mathbf F=x\mathbf i+5xy\mathbf j$ along y=x²/2 from (0,0) to (2,2), in the stated consistent units (nearest integer).

Diagram for GATE 2019 MT question 48

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: 17 to 19

Explanation

Along the path, y=x²/2 and dy=x dx. Therefore $\mathbf F\cdot d\mathbf r=x\,dx+5xy\,dy=[x+(5/2)x^4]dx$. Integrating from 0 to 2 gives $[x^2/2+x^5/2]_0^2=2+16=18$. The work depends on both force components along the curved path.

More Calculus and vector calculus questions

All Calculus and vector calculus questions →