A 50kg crate is being push on a horizontal floor at constant velocity. Given that the coefficient of kenitic friction between crate and floor is hk=0.1 . What is the push force?​

  F = 49 N

Explanation:

For this exercise we must use Newton's second law. Let's set a reference frame with the x axis parallel to the floor.

As they indicate that the box is going at constant speed, its acceleration is zero

Y axis y

       N-W = 0

       N = mg

X axis

        F-fr = 0

        F = fr

the friction force has the formula

      fr = μ N

      fr = μ mg

we substitute

            F = μ m g

let's calculate

            F = 0.1 50 9.8

            F = 49 N

the answer is kevlar