PART IV Solve the following problems. Draw Free Body Diagram and list all the givens.

21.A steele column 12 ft. long and 4.3 in cross sectional area supports a load of 3 Tons. By how much it is shortened if Modulus of elasticity 2.9 x 10 psi.

22.A copper wire 1 mm in diameter and 2 m long is used to support a mass of 5 kg. By how

much doe the wire stretched under this load? What is the minimum diameter the wire can can have if its elastic limit is not tobe exceeded?Elastic limit of copper is 1.5 x 10 N/m?

23. The weight of a 2400 lb car is supported equally by its four tires. The gauge pressure of the air in the tires is 28 psi. Find the area of each tire that is in contact with the ground? where Patmosphere 1.5 psi.