I'll post a file.

Department of Civil and Environmental Engineering

California State University, Fullerton

EGCE 201: Statics

Homework # 3

Due : 10:00 a.m. February 18, 2016

For all problems clearly draw free body diagram.

Q1. In Figure 1, determine the force P required to maintain the 200 kg engine in the position for which θ = 30◦. The diameter of the pulley at B is negligible.

Figure 1: Lifting Engine

Q2. In Figure 2, the lift sling is used to hoist a container having a mass of 500 kg. Determine the force in each of the cables AB and AC as a function of θ. If the maximum tension allowed in each cable is 5 kN, determine the shortest lengths of cables AB and AC that can be used for the lift. The center of gravity of the container is located at G. Note: Weight acts at the center of gravity.

Figure 2: Lift hoisting a container

Q3. In Figure 3, determine the unstretched length of spring AC if a force P = 80 lb causes the angle θ = 60◦ for equilibrium. Cord AB is 2 ft long.Take k = 50 lb/ft.

1

Figure 3: Spring-cord system

Q4. In Figure 4, determine the maximum mass m of the lamp that the cord system can support so that no single cord develops a tension exceeding 400 N.

Figure 4: Cords holding lamp

Q5. In Figure 5, if the tension developed in each of the cables cannot exceed 300 lb, determine the largest weight of the crate that can be supported. Also, what is the force developed along strut AD?

Figure 5: Cables supporting crate

2