1.8-4 The inclined ladder AB supports a house painter (85 kg) at C and the weight (q = 40 N/m) of the ladder itself. Each ladder rail (t, = 4 mm) is sup- ported by a shoe (t, = 5 mm) that is attached to the ladder rail by a bolt of diameter d, = 8 mm. %3D %3D -Typical rung -Ladder rail (t, = 4 mm) Shoe bolt (d, =8 mm) %3D Ladder shoe (t, = 5 mm) Section at base Shoe

1.10-10 A cable and pulley system at D is used to bring a 230-kg pole (ACB) to a vertical position, as shown in the figure part a. The cable has tensile force T and is attached at C. The length L of the pole is 6.0 m, the outer diameter is d = 140 mm, and the wall thickness is t = 12 mm. The pole pivots about a pin at A in figure part b. The allowable shear stress in the pin is 60 MPa and the allowable bearing stress is 90 MPa. Find the minimum diameter of the pin at A in order to support the weight of the pole in the position shown in the figure part a. B Pole 1.0 m Cable 30° Pulley 5.0 m a T A D a 4.0 m (a) d АСВ A Pin Pin support plates PROBLEM 1.10-10

A rigid bar, AB, is pinned at point B. Two other bars, AC and AD, are connected to point A to provide support for AB. We are investigating the behavior of this system under a specific load. Key Details: Bar properties: Material: Steel with Young's modulus (Esteel) of 200 GPa and coefficient of thermal expansion (a) of 11.7 x 10^-6 /°C. Cross-sectional area: AC: 1960 mm² AD: 1250 mm² Length: AC: √2 meters (square root of 2 meters) AD: 1 meter Inclination angles: AC: θ₁ (theta 1) = 30° from horizontal AD: θ₂ (theta 2) = 20° from horizontal Load on bar AB: Idealized linearly increasing load with a maximum value of 30 kN/m at point B. Problem Objectives: Determine the internal forces (axial forces) acting within bars AC and AD due to the applied load on AB.

PREVIOUS ANSWERS A 1,100-N uniform boom at = 55.0° to the horizontal is supported by a cable at an angle 0 = 35.0° to the horizontal as shown in the figure below. The boom is pivoted at the bottom, and an object of weight w = 2,450 N hangs from its top. Ө Pivot W (a) Find the tension in the support cable. 0.0885 Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. KN (b) Find the components of the reaction force exerted by the pivot on the boom. (Assume the positive x-direction is to the right and the positive y-direction is upward. Include the sign of the value in your answer.) horizontal component vertical component kN kN Submit