SIN练习题第4题
4.The ice storm this winter in the province of Quebec strained many wires to the breaking point. In a particular situation, the transmission pylons are separated by 500 m of wire. The top grounding wire is 15° from the horizontal at the pylons, as in the diagram, and has a diameter of 1.5 cm. The steel wire has a density of 7860 kg/m3. When ice (density 900 kg/m3) built up on the wire to a total diameter of 10.0 cm, the wire snapped. What was the breaking stress (force/unit area) in N/m2 in the wire at the breaking point?
You may assume the ice has no strength.
(A) 7.4 X 107 (B) 4.4 X 108 (C) 2.6 X 106 (D) 1.15 X 107 (E) 6.7 X 108
SIN练习题4答案及解析
答案：（B） 解析如下
