To solve this problem it is necessary to apply the concepts related to the Friction Force, which is given from the multiplication between the Normal Force (in a horizontal plane it is equivalent to the mass by gravity) and the kinetic coefficient of friction.
Since the statement the value of the coefficient of friction is not given, so I will assign a value of 0.5 between the crate and the ground. If another value has been provided for this coefficient, it will simply be necessary to replace it in the equation given below.
[tex]F_p = \mu_k N[/tex]
Where,
[tex]\mu_k[/tex]= Coefficient of friction
N = Normal Force
Replacing,
[tex]F_p = 0.5\times 875[/tex]
[tex]F_p = 437.5N[/tex]
Therefore the friction force acting on the crate is 437.5N