This problem is an exact copy of the other one that I just answered for you, about Grace driving 224 miles.
Only the numbers are different, but the way to solve it is exactly the same.
If the crate is moving along the floor in the same direction with a constant speed, it is in dynamic equilibrium. Equilibrium means there is no net force acting on the crate.
Since there is no net force on the crate, there must be a friction force on the crate equal in magnitude and opposite in direction to the applied horizontal force. Therefore the force of friction acting on the crate is 100N.
the football player has speed
Endurance is the ability to complete extended periods of physical activity