A dog (mass 13.3 kg) sits on a sled (mass 5.5 kg) that is being pushed with a force of 33 N on a flat snowy surface. If the acceleration of both is 1.4 m/s2, what is the coefficient of kinetic friction for the sled sliding on the snow?

Question

anonymous · Answer

Sorry. I really am bad at this stuff

anonymous · Answer

Okay are they wanting us to combine the masses or keep them separate?

photon336 · Answer

i would combine them

photon336 · Answer

remember the dog is on the sled both are moving at the same acceleration

anonymous · Answer

m= 18.8
a = 1.4 m/s^2
Fpush = 33N

photon336 · Answer

|dw:1447122487797:dw|

photon336 · Answer

always make a diagram too

photon336 · Answer

does this make sense to you ? 

$$F_{applied} - F_{kinetic friction} = Ma_{net} $$

photon336 · Answer

net acceleration is 1.4 m/s^2

anonymous · Answer

Why is it static friction if the sled is moving?

photon336 · Answer

well there is no more static friction because that was overcome already

photon336 · Answer

but still when you move there's still friction that's opposing the direction of your force and that's called kinetic friction

anonymous · Answer

Okay so it's 33N-Fkinetic = (18.8 kg)(1.4m/s^2)

anonymous · Answer

33N-Fkinetic = 26.32N

anonymous · Answer

-Fkinetic= -6.68

anonymous · Answer

-1(-Fkintetic= -6.68) = Fkinetic = 6.68N

anonymous · Answer

Is that it?

photon336 · Answer

yep but they asked you for something else