Question

the force f2=15.0 N acts at the point 70.0cm

Answer 1

Since you've given a force magnitude and a distance, I assume the actual question is asking for Work done on the point. Work, of course, is equal to Force times Distance. First, we have to convert the units of distance into meters, which is the SI unit. That gives us a distance of x = 0.700m. Given also that F = 15.0N, we can quickly multiply the two quantities to get W = Fx = (15.0N)(0.700m) = 10.5 N.