View Full Version : Kinetic friction
Gostronge
Jun 24, 2007, 07:31 PM
A curler throws a curling rock with a speed of 10.5m/s down a curling rink. The mass of the curling rock is 20kg. The coefficent of kinetic friction between the rock and the ice surface of the rink is 0.05 The length of the rink is 28.4m
The speed of the curling rock when it reaches the opposite end of the rink will be?
Capuchin
Jun 24, 2007, 11:37 PM
well the frictional force is F=\mu N where N is the normal force
then you can use F=ma to work out the deceleration rate.
Gostronge
Jun 25, 2007, 06:49 PM
well the frictional force is F=\mu N where N is the normal force
then you can use F=ma to work out the deceleration rate.
i have tried that step but uable to get the correst answer. I think the distance and there speed of the curling plays a important factor to getting the right answer.
this is a multiple choice question with the following selection:
a 11.8 m/s
b 9.08 m/s
c 9.81m/s
d 82.3m/s
Capuchin
Jun 25, 2007, 11:50 PM
Well I make it 10.36m/s, so I'm doing something wrong, anyone else want to chime in?
ebaines
Jun 26, 2007, 06:58 AM
I get one of the multiple choices. I used Capuchin's suggestion setting ma = \mu mg to calculate the rock's deceleration, and then used the formula:
v_f ^2 - v_i ^2 = 2 a d
to determine the final velocity v _f after traveling 28.4m.
Capuchin
Jun 26, 2007, 09:07 AM
Ah yes I see what I did wrong, I do get one of the answers now.