8. A horizontal force is applied to the handle of the level in order to pull the two metal pieces and .

1) Determine the moment of about A and the tension T in the cable.

2) Given , what is the probability that T is greater than 334 lb?

3) F is normally distributed. As a result, T is also normally distributed, and its distribution is . The strength of the cable is . If the probability of failure is , determine the distribution of F.

Solution

1)

Ans.

g

Ans.

2)

We know, so we can calculateand

Ans.

3)

From the figure, we have

Thus

We know

Thus

Since we have

The distribution of F is: Ans.