8/10/2019 Quiz no. 3

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1.

A stepladder consisting of two legs pinned together at C is resting on

a rough floor. Will a 800N worker be able to change the light bulb if

he is required to climb to a height of 1.3 m? The uniform legs AC and

BC weigh 110 N and 70 N, respectively. The coefficient of static

friction atA andB is 0.48.

2.

The man is trying to push the homogeneous 20-kg ladderAB up a wall

by applying the horizontal forceP. Determine the smallest value ofP

that would move the ladder. The coefficient of static friction between

the ladder and both contact surfaces is 0.3.

3. Determine the forces in the members BD and CD of the

truss in the figure. All triangles are equilateral.

4.

Determine the forces in members AE and DC. State if the

members are in tension or compression.

8/10/2019 Quiz no. 3

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5.

Determine the smallest force P required to pull out

wedge A. the crate has a weight of 300lb and the

coefficient of static friction at all contacting surfaces is

0.3. Neglect the weight of the wedge.