The Young’s modulus of aluminum is 69GPa, of nylon is 3GPa, of tungsten is 400GPa, and of copper is 117GPa. If equal-size samples were put under equivalent tensile stresses, how would you rank the materials by the degree to which they would be elongated?
Rank the wires from least elongation (least stretch) to most elongation (most stretch).
1. Aluminum
2. Tungsten
3. Nylon
4. Copper

To place a communications satellite into a geosynchronous orbit at an altitude of 22,240 mi above the surface of the earth, the satellite first is released from a space shuttle , which is in a circular orbit at an altitude of 185 mi, and then is propelled by an upper-stage booster to its final altitude. as the satellite passes through a, the booster's motor is fired to insert the satellite into an elliptic transfer orbit. the booster is again fired at b to insert the satellite into a geosynchronous orbit. knowing that the second firing increases the speed of the satellite by 4810ft/s, determine (a.) the speed of the satellite as it approaches b on the elliptic transfer orbit, (b.) the increase in speed resulting from the first firing at a.