Question

Find the work done by force, F = 8i - 6j + 9k move from <0, 10, 8> to <6, 12, 20>

Answer 1

Answer:

$work \: done = f.ds \\ = (8i - 6j + 9k).(6i + 2j + 12k) \\ = 48 - 12 + 108 \\ = 36 + 108 \\ = \: \: 144 \: \: joules$

Explanation:

$f = 8i - 6j + 9k \\ \\ ds = (6 - 0)i + (12 -1 0) j+ (20 - 8)k \\ \\ ds = 6i + 2j + 12k \\ \\ work \: done = f.ds \\ = (8i - 6j + 9k).(6i + 2j + 12k) \\ = 48 - 12 + 108 \\ = 36 + 108 \\ = \: \: 144 \: \: joules$