An elevator is suspended by a heavy steel cable. If this cable were replaced by two steel cables each having the same length as the original one but half its diameter, how would the amount of stretch in the pair of thin cables (st) compare with that of the original cable (so)?

A steel wire of diameter 4.72 mm stretches by 7.98 mm when a 320 -kg piece of equipment is suspended from it. If the wire had a diameter of 4.75 mm instead, by what distance in mm would the equipment stretch the wire?

A rigid bar of mass M is supported symmetrically by three wires each of length l. Those at each end are ofcopper and the middle one is of iron. The ratio of their diameter, if each is to have the same tension, is equal to (a)YcopperYiron(b) √YironY copper(c)Yiron2Ycopper2(d)YironYcopper

Find the force exerted by the biceps muscle in holding a 1.00-L milk carton (weight 9.90 N) with the forearm parallel to the floor. Assume that the hand is 35.0 cm from the elbow and that the upper arm is 30.0 cm long. The elbow is bent at a right angle, and one tendon of the biceps is attached to the forearm at a position 5.00 cm from the elbow, while the other tendon is attached at 30.0 cm from the elbow. The weight of the forearm and the empty hand is 16.9 N, and the center of gravity of the forearm with hand is at a distance of 16.5 cm from the elbow.

A mine elevator is supported by a single steel cable 2.5 cm in diameter. The total mass of the elevator cage and occupants is 670 kg. By how much does the cable stretch when the elevator hangs by (a) 12 m of cable and (b) 362 m of cable? (Neglect the mass of the cable.)

Two rods, one made of copper and the other of steel, have the same dimensions. If the copper rod stretches by 0.15 mm under some stress, how much does the steel rod stretch under the same stress?

A sample of tendon 3.00 cm long and 4.00 mm in diameter is found to break under a minimum forceof 128 N. If instead the sample had been 1.50 cm long and of uniform composition and crosssectional area, what minimum force would have been required to break it?

What type of stress are you applying when you press on the ends of a wooden rod? When you pull on its ends?

A weight of (50kg) affects the lower end of a steel rod of length (80cm) and diameter (0.60cm). What is the magnitude of the elongation of the penis, if you know that the Junk modulus of the bar is equal to (190GPa)?