physics
posted by Leo on .
Hello everyone, I need help with this question:
A bartender slides a glass of beer down a bar with an initial velocity of 2m/s. The coefficient of kinetic friction of the bar is 0.05 and the length of the bar is 3m and the height of the bar is 1m. The mas 0.5kg. How far from the bar will the glass hit the ground?
Thanks very much!

KE1=KE2+W(fr)
KE2=KE1 W(fr)=
=mvₒ²/2  μmgs=
=0.5(2²/2  0.05•9.8•3)=0.265 J.
KE2= mv²/2=0.265 J.
v=sqrt(2•KE2/m) =
= sqrt (2•0.265/0.5)=
=1.03 m/s.
h=gt²/2 =>
t =sqrt(2h/g)=
=sqrt(2•1/9.8) =0.45 s
s=v(x) •t=1.03•0.45=0.46 m.