The spool in the given figure weighs 25 N, and its center of gravity is located at the geometric center. The weight of block C is 50 N. The coefficients of static friction at the two points of contact are as shown. Determine the largest horizontal force P that can be applied without disturbing the equilibrium of the system. Hs=0.3- #₁=0.4 C A B 08 120 Dimensions in mm P

A uniform ladder 5 m long and weighing 80N rests against on a vertical wall at B and one end at A (on the ground). The angle of friction at all contact surfaces is 21.8°. Find the smallest angle 0 at which the ladder can be inclined with the horizontal before it is on its verge of slipping.

The boxes are at rest. The pulley is massless. Fpull makes an angle 0 with respect to the incline. (i) Draw free body diagrams for m, and m, for the situation outlined in part (ii). (ii) What maximum force, Foull, Can you apply to m, and have it remain at rest? In terms of the given information. Just give the equation (or equations) needed to solve for the force. Do not simplify or isolate for Fpull, but make sure it is the only unknown. pull Given information: B (angle of incline with horizontal) e (angle Fpull makes with incline) m, (mass of box 1) m2 (mass of box 2) H (distance m, is above the ground) • H, (static friction coefficient, incline and box 1) He (kinetic friction coefficient, incline and box 1) m1 m2

A former student of mechanics wishes to weigh himself but has access only to a scale A with a capacity limited to 100 lbs and a small 24 lb spring dynamometer B. With the rig show he discovered that when he exerted a pull on the rope so that B registers 20 lb, the scale A reads 80 lbs. What is the correct weight?

The 250 lb uniform crate (center of gravity at G) shown in the figure must be moved without tipping. The applied force P is horizontal. 1.5 ft 1.5 ft Determine: a. The largest coefficient of static friction between the crate and the floor that allows the crate to slide and 2.5 ft P. not tip 4.5 ft b. The corresponding magnitude of P 3.5 ft Include all needed FBD's to solve, and put units on your answers.

Each of the bodies shown is homogeneous and has a mass of 30 kg. Assume friction at all contact surfaces. Draw the fully dimensioned FBD for each body and determine the number of unknowns.

The uniform rod BC weighs 32.2 lb. The rod is connected to the frame D by a frictionless pin C and a cord AB as shown. Calculate the maximum value of the applied force P for which rod BC will not “rise up”.

End B of the uniform 2.7-kg bar AB is connected to a small roller that moves in a horizontal slot. The other end of the bar is pinned to the homogeneous 1.8-kg disk that rolls without slipping on the vertical surface. The spring attached to A has a free length of 0.3 m and a stiffness of 58 N/m. After the system is becomes horizontal. Determine the magnitude of the force P that acts on the bar at B. 2.1 m 0.24 m 0.9 m www 1.8 kg 1.5 m 2.7 kg P

1.2 m \30° 15 m Fig. P4.1

Three identical steel balls, each of mass m=85kg, are placed in the cylindrical ring which rests on a horizontal surface and whose height is slightly greater than the radius of the balls. The diameter of the ring is such that the balls are virtually touching one another. A fourth identical ball is then placed on top of the three balls. Determine the force P (in N, roundoff to 2 decimal places exerted by the ring on each of the three lower balls.