Grade 11 Forces/Kinetics Physics Problem?
A hockey puck is sliding across the ice. Its initial speed is 9.0 m/s. The coefficient of kinetic friction between the puck and the ice is 0.16. How far will the puck slide before coming to a stop?
My teacher says that you don't need the mass to answer this question. And if you could show steps it would be much appreciated. Thanks!
Comments
Lets start with what we know:
Vi=9.0m/s___μ=0.16___di=0m___a=?
Vf=0m/s____m=Mkg___df=?
'i' means initial, 'f' means final. we have a place holder for mass, you'll see that it will work out, just stick it in like you would any number. 'a' is an unknown acceleration and 'df' is the distance we are asked to find.
Now, the main principle we will be using is Newton's 2nd Law: F=ma. Once we find 'a' we can use kinematics to find the distance. Before that we need to figure out what forces are acting on the puck. You will need these equations, hope that helps, good luck
Friction Force = μmg
Vf^2=Vi^2+2ad
N=mg
Ff=nu*N = (.16)mg
Use Work Energy Theorem
Wf=Ff*x=(.16)mgx
KE=(1/2)mv^2
When v=0, the Kinetic Energy is lost as Work due to friction
KE=Wf
x = v^2/2(.16)g = 25.8 m