A force F=(5 hati+3 text hatj+2 hatk)N is applied over a particle which displaces it from its origin to the point r=(2 hati- hatj)m . The work done on the particle in joules is

Question

A force F=(5 hati+3 text hatj+2 hatk)N is applied over a particle which displaces it from its origin to the point r=(2 hati- hatj)m . The work done on the particle in joules is (A)  -7  (B)  +7  (C)  +10  (D)  +13

Tardigrade Admin · Accepted Answer

Work done is displacing the particle W=F.r=(5 hati+3 hatj+2 hatk).(2 hati- hatj) =5× 2+3× (-1)+2× 0=10-3 =7J

Q. A force $F = (5 \hat{i} + 3 \hat{j} + 2 \hat{k}) N$ is applied over a particle which displaces it from its origin to the point $r = (2 \hat{i} - \hat{j}) m$ . The work done on the particle in joules is

$- 7$

$+ 7$

$+ 10$

$+ 13$

Work done is displacing the particle $W = F . r = (5 \hat{i} + 3 \hat{j} + 2 \hat{k}) . (2 \hat{i} - \hat{j})$ $= 5 \times 2 + 3 \times (- 1) + 2 \times 0 = 10 - 3$ $= 7 J$

Q. A force F=(5i^+3j^​+2k^)N is applied over a particle which displaces it from its origin to the point r=(2i^−j^​)m . The work done on the particle in joules is

−7

+7

+10

+13