Question

Suppose a 58-N sled is resting on packed snow. The coefficient of kinetic friction is 0.11. If a person weighing 655 N sits on the sled, what force is needed to pull the sled across the snow at constant speed?

Answer 1

Answer:

You have to apply force of 78.43 N to pull the sled or person across the snow at constant speed

Explanation:

Given data

Sled force F₁=58 N

Person weight F₂=655 N

Coefficient of kinetic friction u=0.11

To find

Friction Force

Solution

To pull the sled across the snow means the force you apply must be equal to and opposite the force of frictional.  

First we need to find the Total normal force

So

$F_{Normal-Force}=F_{1}+F_{2}\\F_{Normal-Force}=58N+655N\\F_{Normal-Force}=713N$

Now the force of friction

$F_{Friction-Force}=u_{coefficient}*F_{Normal-Force}\\F_{Friction-Force}=0.11*713N\\F_{Friction-Force}=78.43N$

So you have to apply force of 78.43 to pull the sled or person across the snow at constant speed