📐 Mathematics · Vector Algebra · JEE

The work done by F = 2i - j + k along displacement from A(1,0,0) to B(2,1,3) is:

Answer: 4.

Correct answer: A. 4

Explanation: Displacement d = B−A = (2−1, 1−0, 3−0) = (1,1,3). Work W = F·d = 2(1)+(−1)(1)+1(3) = 2−1+3 = 4 units. Answer: W = 4.

Triangle law of vector addition: placing vector b at the head of vector a, the diagonal from the start to the final head gives the resultant a + b.

Concept context

Vectors, dot product, cross product, and geometric applications