# physics

posted by
**farid** on
.

A strip of rubber originally 75 mm long is stretched until it is 100 mm long.

a.What is the tensile strain

b.Why has the answer no units?

c.The greatest tensile stress which steel of a particular sort of a particular sort can withstand without breaking is about 10>9 N m>-2.A wire of cross-sectional area 0.01 mm>2 is made of this steel. What is the greatest force that it can withstand?

d.Find the minimum diameter of an alloy cable, tensile strength 75 MPa, needed to support a load of 15 kN.

e.Calculate the tensile stress in a suspension bridge supporting cable, of diameter of 50 mm, which pulls up on the roadway with a force of 4 kN.

F.Calculate the tensile stress in a nylon fishing line of diameter 0.36 mm which a fish is pulling with a force of 20 N.

g.A large crane has a steel lifting cable of diameter 36 mm. The steel used has a Young modulus of 200 GPa.When the crane is used to lift 20 kN, the unstretched cable length is 25.0 m. Calculate the extension of the cable