How Does Friction Affect a Hockey Puck's Acceleration and Distance on Ice?

[Power24]

A Hockey puck of a mass 350g is sliding along the ice at 6.0 m/s[n] when it hits a rough patch of ice that exerts a frictional force of 0.42N

i)Determine the pucks acceleration
ii)determine how far the puck will slide before stopping.

f=ma a=f/m a=.42/.35 this gives me 1.2 or something but it is slowing down therefore it should a negative, should I rewrite the equation giving aa negative value or is there a better equation for the information given.

 

[thenewbosco]

the 0.42 should have a negative attached to it since it acts opposite the direction of motion

 

[Power24]

is the value still 0.42 though?

 

[carltonblues]

I thought the mass was irrelevant?

 

[Power24]

well F=ma is relavant to the unit I am working on, however it also incorporates other units so I could be way off but I am just dealing with what I have.