How far do the dishes move during the 0.20s it takes to pull out the tablecloth? The coefficient of kinetic friction between the cloth and the dishes is μk = 0.12.

Question

anonymous · Answer

Well we assume it has mass $m$ I suppose.  Then the normal force will be $mg$.

anonymous · Answer

So $\mu_kmg$ would be the force that acts on the dishes for the fifth of a second.

anonymous · Answer

This is going to be constant acceleration.

nottim · Answer

Can we assume mass to be 1?

anonymous · Answer

So we can integrate twice and get the formula: $\Delta x =\frac 12at^2=\frac 12u_kmgt^2$

anonymous · Answer

I suppose you could, but I believe the end result is proportional to the mass.  Lighter things will move less than heavier things because the friction is different.

anonymous · Answer

wait, scratch that...

anonymous · Answer

Since $a=u_kg$ I suppose mass is irrelevant.

anonymous · Answer

Should have said $\Delta x =\frac 12at^2=\frac 12u_kgt^2$

anonymous · Answer

So just plug in your numbers.

nottim · Answer

but we aren't given acceleration? i think

anonymous · Answer

gravitational acceleration... assume it is on Earth

nottim · Answer

for both a and g?

anonymous · Answer

No, $a=u_kg$

nottim · Answer

i see