# force polygon

## Problem 525 | Friction

**Problem 525**

A uniform ladder 4.8 m ft long and weighing W lb is placed with one end on the ground and the other against a vertical wall. The angle of friction at all contact surfaces is 20°. Find the minimum value of the angle θ at which the ladder can be inclined with the horizontal before slipping occurs.

## Problem 361 | Equilibrium of Non-Concurrent Force System

**Problem 361**

Referring to Problem 359, if T = 30 kN and x = 1 m, determine the angle θ at which the bar will be inclined to the horizontal when it is in a position of equilibrium.

## Problem 360 | Equilibrium of Non-Concurrent Force System

**Problem 360**

Referring to Problem 359, what value of T acting at x = 1 m from B will keep the bar horizontal.

## Problem 359 | Equilibrium of Non-Concurrent Force System

**Problem 359**

A 4-m bar of negligible weight rests in a horizontal position on the smooth planes shown in Fig. P-359. Compute the distance x at which load T = 10 kN should be placed from point B to keep the bar horizontal.

## Problem 351 | Equilibrium of Non-Concurrent Force System

**Problem 351**

The beam shown in Fig. P-351 is supported by a hinge at A and a roller on a 1 to 2 slope at B. Determine the resultant reactions at A and B.

## Problem 323 | Equilibrium of Force System

**Problem 323**

The truss shown in Fig. P-323 is supported by a hinge at A and a roller at B. A load of 20 kN is applied at C. Determine the reactions at A and B.

## Problem 322 | Equilibrium of Force System

**Problem 322**

The Fink truss shown in Fig. P-322 is supported by a roller at A and a hinge at B. The given loads are normal to the inclined member. Determine the reactions at A and B. Hint: Replace the loads by their resultant.

## Problem 316 | Equilibrium of Concurrent Force System

**Problem 316**

Determine the values of α and θ so that the forces shown in Fig. P-316 will be in equilibrium.

## Problem 315 | Equilibrium of Concurrent Force System

**Problem 315**

The 300-lb force and the 400-lb force shown in Fig. P-315 are to be held in equilibrium by a third force F acting at an unknown angle θ with the horizontal. Determine the values of F and θ.