Question

A man pushes a block of ice across a frozen pond at a constant velocity. While the coefficients of static and kinetic friction for ice are low, they are not zero. Consider this problem to involve friction. If necessary, use Fs for the force of static friction, and Fk as the force of kinetic friction.
Required:
Draw the Free Body Diagram for the block of ice.

Answer 1

Answer:

   F₁> F₂

Explanation:

For this exercise Newton's second law is used, in the adjoint we can see the unapplied forces in this exercise.

Y axis y

        N- W = 0

in this axis there is no movement

X axis

          F -fr = m a

as they indicate that the velocity is consonant the acceleration is worth zero

          F - fr = 0

friction force has the expression

           fr = μ N

           fr = μ mg

we substitute

           F = μ m g

by the time the block is stopped the deferred force is

           F₁ = μ_s m g

when it begins to move the force should decrease to

           F₂ = μ_k k m g

as the static coefficient is greater than the dynamic coefficient

             F₁> F₂