Work done by a force F on a body is W = F .s, where s is the displacement of body. Given that under a force F = (2 hat I +3 hat j +4 hat k) N a body is displaced from position vector r_1 = (2 hat I +3 hat j + hat k) m to the position vector r_2 = (hat i +hat j+ hat k) m. Find the work done by this force.
Answers
work done by the force is 8 J
given the force vector=2i+3j+4k
position vectors r1=2i+3j+k
r2=i+j+k
displacement vector=r1 - r2
= -i - 2j
work done =I F I I S I cosФ
value of cosФ is 1 if the force is in same direction
hence work done= (2i+3j+4k) . (i+2j)
=8 J
Explanation:
work done by the force is 8 J
given the force vector=2i+3j+4k
position vectors r1=2i+3j+k
r2=i+j+k
displacement vector=r1 - r2
= -i - 2j
work done =I F I I S I cosФ
value of cosФ is 1 if the force is in same direction
hence work done= (2i+3j+4k) . (i+2j)
=8 J