Answer:
W = 71J
Explanation:
Given force F = (5i+5jā1k)N
d = Īr
r1 = (ā5,ā3,ā4)m
r2 = (2,5,0)m
Īr = r2 ā r1 = (2-(-5), 5-(-3), 0-(-4))
Īr = (2+5, 5+3, 0+4) = (7i+ 8j +4k)m
W = Fā¢d = (5i+5jā1k)ā¢(7i+ 8j +4k)
W = 5Ć7 + 5Ć8 +-1Ć4 = 35 + 40 - 4
W = 71J