Question

A force of (3î +4ĵ) newton acts on a body and displaces it by (3î +4ĵ) m. the work done by the force is

Answer 1

Your answer is ---

Given,

force f = 3i^ + 4j^

displacement d = 3i^ + 4j^

force and displacement is same

So, angle between force and displacement is 0

Now , according to formula

W = fd cos@

=> W = (3i^+4j^).(3i^+4j^) × cos0°

as we know that formula of work is based on the dot product of force and displacement .

=> W = (3×3 + 4×4 ) × 1 [ cos0° = 1]

=> W = 9 + 16

=> W = 25Joule

Hence, work done by force is 25joule .


【 Hope it helps you 】

Answer 2

Answer:

25 J

Explanation:

work done =force.displacement

                  = (3i +4j).(3i+4j)

                  =9+16

                   =25 N