- #1
IamMoi
- 13
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Homework Statement
A 0.170 kg hockey puck is initially moving at 21.2 m/s [W] along the ice. The coefficient
of kinetic friction for the puck and the ice is 0.005.
(a) What is the speed of the puck after traveling 58.5 m? ans: 21.1 m/s
(b) After being played on for a while, the ice becomes rougher and the coefficient of
kinetic friction increases to 0.047. How far will the puck travel if its initial and final
speeds are the same as before?
Homework Equations
Fnet=ma
Fg=mg
Fk=μk.Fn
Vf[itex]^{2}[/itex]=Vi[itex]^{2}[/itex]+2ad
The Attempt at a Solution
a.) Fnet=Fk
ma=μk.Fn
ma=μk.mg
a=[itex]\frac{(0.05)(0.170kg)(9.8m/s^{2})}{0.170kg}[/itex]
=0.049m/s[itex]^{2}[/itex]
Vf[itex]^{2}[/itex]=Vi[itex]^{2}[/itex]+2ad
=[itex]\sqrt{(21.2)^{2}-(0.049)(58.5)}[/itex]
=21.13m/s
b)Fnet=Fk
ma=μk.Fn
ma=μk.mg
a=[itex]\frac{(0.047)(0.170kg)(9.8m/s^{2})}{0.170kg}[/itex]
=0.04606m/s[itex]^{2}[/itex]
.. then i don't know what's next..