Question 23

Mathematics Scalar and Vector Products Hard

Forces 3î + 2ĵ + 5k̂ and 2î + ĵ - 3k̂ are acting on a particle and displace it from the point 2î - ĵ - 3k̂ to the point 4î - 3ĵ + 7k̂. The work done by the force is:

(A) 18 units.
(B) 30 units.
(C) 24 units.
(D) 36 units.
View Dynamic Solution & Explanation
Correct Solution: Option C

Step-by-step Solution:

Resultant force \(= 5i + 3j + 2k\) and the displacement is \(2i - 2j + 10k\) Work done is \[ (5i + 3j + 2k) \cdot (2i - 2j + 10k) \] \[ = (5 \times 2) + (3 \times -2) + (2 \times 10) = 10 - 6 + 20 = 24 \]