physics
posted by sammi .
what is the value for k if a spring stretches 0.4m when submitted to a 1800N force?
How much force is needed to keep a 23 kg box moving at a constant velocity across a warehouse floor if the coefficient of friction between the box and the floor is 0.88?

Both of these are straightforward uses of standard formulas. I will be happy to critique your thinking.

i'm not very good at physics
for the first one do i use the formula F=Kx to make the answer 4500 ?
and for the second i really have no idea what formula to use