An object with a mass of 4 kg is hanging from a spring with a constant of 3 (kg)/s^2. If the spring is stretched by  13 m, what is the net force on the object?

Weight of object = text(mg) = 4 text(kg) × 10 text(ms)^-2 = 40 text(N) (downwards)
Spring Force = text(kx) = 3 (text(kg))/text(s)^2 × 13 text(m) = 39 text(N) (upwards)
$\textrm{N e t F \mathmr{and} c e} = 40 \textrm{N} - 39 \textrm{N} = 1 \textrm{N}$ (downwards)