A 23.3-kg ladder has a length of 7.50 m. With the bottom of the ladder on horizontal ground, it leans up against the vertical wall of a house; its point of contact with the house is 7.09 m above the ground. If the point of contact with the house is friction less but the point of contact with the ground is not friction less, what is the magnitude of the frictional force of the ground acting on the ladder?