what is the Uk? the distance? the acceleration or deceleration?
so you want the friction? oh you want to find out muon not U. O.o
A 2500 Kg car is heading east at 20 m/s. IT slams on the breaks to avoid hitting a deer. It takes the car 50 meters to stop, what is the Uk between the car and the road.
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Well I've been absent for school for two days, which is coincidentally when he was teaching this stuff.
So I'm not even exactly sure what Uk is.
I assume I'd use V^2=V0^2+2da ?
I assume you want Friction
yes, you use
where,
* v=0m/s
* u=20m/s
* a=?
* x=50m
sub the numbers in
rearrange the equation to find a.
since Newton's second law defines where F= force of overall system not friction
using the equation
where F = friction
then rearrange the equation to find F.
you should get
and
where
To find out the reaction force, using the y directional force:
Then
rearrange to find
is the coefficient of kinetic friction.
, where is the force of sliding friction, and is the normal force between the surfaces in contact.
using the equation , you can determine the car's acceleration ... then use Newton's 2nd Law of motion,
, substituting for the net force ... then you can find from the equation above.