physics
posted by sammi on .
i'm not very good at physics and i have an exam tomorrow!!
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
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?

k=force/distance
moving at a constant veloicty? Well you have to supply force equal to friction: mg*mu 
k=F/x
=1800/0.4
=4500 N/m