3.0×10^4 N. (a) How much will the cable stretch when the helicopter is hovering? (b) If the yield strength of the steel in the
cable is 2.1×10^8 N/m^2 , at what rate can the helicopter accelerate upward before the cable deforms permanently?
(a) m
(b) m/s^27.7 Two rods with identical dimensions are placed end to end to form a new rod. If one of the smaller rods is aluminum alloy and
the other is titanium, what is the effective Young's modulus of the large rod?
N/m^2
Section 8 - Volume stress
8.1 The deepest point in the seven seas is the Marianas Trench in the Pacific Ocean. The pressure in the deepest parts of the
Marianas Trench is
1.1×10^8 Pa. Pressure at the surface of the ocean is 1.0×10^5 Pa. If a mass of salt water has a volume of 1.6 m^3 at the surface
of the ocean, what will be its volume at the bottom of the Marianas Trench?
m^38.2 If a spherical glass marble has a radius of 0.00656 m at 1.02×10^5 Pa, at what pressure will it have a radius of 0.00650 m?
Pa8.3 The pressure on the surface of Venus is about 9.0×10^6 Pa, and the pressure on the surface of Earth is 1.0×10^5 Pa. What
would be the volume strain on a solid stainless steel sphere if it were moved from Earth to Venus?
8.4 A sealed, expandable plastic bag is filled with equal volumes of saltwater and mercury. The volume of the bag is 0.120 m^3 at
a pressure of 1.01×10^5 N/m^2. What is the change in volume of the bag when the pressure increases to 1.09×10^5 N/m^2?
Assume that the bag exerts no force.
m^3