A ladder of length 10 m and mass 25 kg leans against a smooth wall such that it is at an angle of 57∘ to the horizontal.  A man of mass 70 kg stands at the point A marked in the diagram, a distance d from the foot of the ladder. The coefficient of friction between the ground and the ladder is 0.1. A)Find the magnitude of the normal reaction force N acting at the foot of the ladder.

B) What is the relationship between the magnitude of the friction F acting on the foot of the ladder, and the magnitude of the normal reaction R, acting at the top of the ladder. Write your answer as a mathematical equation (using the "=" sign) involving F and R