Question

A force F = (2î - j +4k)N displaces a particle upto
d = (3i +2j- k)m, calculate work done.
(1) Zero
(2) 8J
(3) 4J
(4) 12 J
​

Answer 1

Answer:

1) Zero

Explanation:

Work done = Force . displacement

= (2î - j +4k) . (3i +2j- k)

= 6 - 2 - 4

= 6 - 6

=0N

Answer 2

Answer:

Work done = Zero

Explanation:

Given: Force, f = (2î - j +4k)N

displacement, s = (3i +2j- k)m

To find: the work done.

Solution: #For work done, we know that:

                     W = F.s

where, W = work done

            F = force vector

            s = displacement vector

            . denotes dot product.

Putting the given values in the formula, we get:

                  W = (2î - j +4k).(3i +2j- k)

                  W = 6 - 2 - 4

                  W = 6 - 6

                  W = 0

Hence, the #work done is zero.