Curling stone coming to rest - friction

1. May 31, 2010

ghostbuster25

This is just a revision question for an exam i have in a couple weeks.

I think i kow the answer but just want to double check.

a curling stone is released with an instial speed of 3.1 m/s
the coefficent of sliding friction between the stone and ice is 0.017
What is the distance the stone will come to rest?
A 14m B 19m C 29m D 58m E Impossible to tell without mass

I believe it to be E

IF i did have the mass what equation would i need?
$$\mu$$$$_{}slide$$ * mg ??

Many thanks

Last edited: May 31, 2010
2. May 31, 2010

proculation

Re: friction

you sure ? If a ton of steel is on a ice and I push it to give it a momentum, will it stop at the same place than a curling stone of 10kg ?

3. May 31, 2010

proculation

Re: friction

btw it was a joke. You had it almost right :P

coefficient of dynamics friction * Force which equals Mass times Acceleration.

4. May 31, 2010

ghostbuster25

Re: friction

ok re-looked at it and have decided on D 58m as D=V2/the coefficent of sliding friction * gravity (9.8 m/s)

That look correct?

5. May 31, 2010

proculation

Re: friction

How can you tell the acceleration ? (which is negative) you conclude it is the gravity ?

6. May 31, 2010

ghostbuster25

Re: friction

well the equation i have is D=V2/$$\mu$$slide * g

I just put in my values of 3.1 m/s2/ 0.017*9.8 m/s

It gave me an answer of 57.6 which is the same as answer D 58m (2sf)

7. May 31, 2010

proculation

Re: friction

I already told you you were right.

It's just my way to teach. To make sure you understood and looked at your response again to be sure.

8. May 31, 2010

ghostbuster25

Re: friction

ha ha oh right, ok thanks
Do you know much about collisions in three dimensions between 2 objects? i.e (vbx,vby)?
:)

9. May 31, 2010

proculation

Re: friction

It's the same thing then between two objects in 2 dimensions. You just add another dimension.

You seperate the forces in x, y, z instead of only x and y. That's it.

10. May 31, 2010

ghostbuster25

Re: friction

sorry ive been an idiot, i meant in 2 dimensions.
ill tell you the question....

2 objects with masses A 0.60kg and B 0.45kg are travelling towards one another parallel and anti parallel at uAx 1.5m/s and uBx -2.0m/s
the velocity of A after collision is (0,12)m/s what is (vBx,vBy) of B after collision?

I just cant find in my text how to do it for (x,y)

11. May 31, 2010

proculation

Re: friction

Hint: 3rd law of Newton.

12. May 31, 2010

ghostbuster25

Re: friction

so if object A has an opposite but equal in magnitude force on object B when they collide then the force acting on B would be f=ma which would be 0.9N, if i rearrnged to find for v i get v=f/m which gives me 2m/s but as B is travelling at -2m/s it would reusult in 0m/s so B would come to a stand still and have (vBx,vBy) (0,0)m/s

is that sort of the way to go?

13. May 31, 2010

proculation

Re: friction

You "can" do it that way. But the best way is to go with the 3rd law of newton: the conservation of energy.

Or I may say, the momentum. m1 x v1 = m2 x v2

14. May 31, 2010

ghostbuster25

Re: friction

yer i was going to ask if there was a better way of doing it. That makes sense :) Thanks