if f1= 3i + 5j + 6k and f2= 2i + 3j - 4k both measure the newton are displaced by d= 3i - 2j + 4k measure the metre, find the workdone

Answer 1

work=f1 dot d + f2 dot d
work=(3i + 5j + 6k).( 3i - 2j + 4k ) + (2i+3j-4k).(3i-2j+4k)
work= 9-10+24+6-6-16
work=add them up.