Q. A 5 m ladder of mass 25 kg is placed in a position where its inclination to a vertical wall is at 30?. A 100 kg man is to climb the ladder. If the coefficient of static friction is 0.25 the height along ladder at which the slipping will be induced would be

• (A) 2.4 m
• (B) Friction always acts to oppose the relative motion of the free body
• (C) If static friction is acting, the value of the friction force may vary from zero to its maximum value
• (D) The force of friction is always normal to the surface