constant force F=5i+5jāˆ’1kF=5i+5jāˆ’1k is applied to an object that is moving along a straight line from the point (āˆ’5,āˆ’3,āˆ’4)(āˆ’5,āˆ’3,āˆ’4) to the point (2,5,0).(2,5,0). Find the work done if the distance is measured in meters and the force in newtons. Include units in your answer.

Respuesta :

Answer:

W = 71J

Explanation:

Given force F = (5i+5jāˆ’1k)N

d = Δr

r1 = (āˆ’5,āˆ’3,āˆ’4)m

r2 = (2,5,0)m

Ī”r = r2 – r1 = (2-(-5), 5-(-3), 0-(-4))

Δr = (2+5, 5+3, 0+4) = (7i+ 8j +4k)m

W = F•d = (5i+5jāˆ’1k)•(7i+ 8j +4k)

W = 5Ɨ7 + 5Ɨ8 +-1Ɨ4 = 35 + 40 - 4

W = 71J