A mass is being pulled forward at a constant velocity of 3 m/s with a force of 15 N. The weight of the mass is 9.0 N.

What applied force must be exerted so that the mass will accelerate to 14 m/s in 4.0 seconds.

*Another one I don't understand. I even tried converting the newtons and still nothing.

2 answers

mass = 9/g = 9/9.81 kg = .917

friction or other force holding it back = 15 Newtons
so
F - 15 = ma = .917 (a)
but a = 14/4
so
F = 15 + .917(14/4)
= 18.2 N
yup