A steel rod with a cross-sectional area of 0.20 in² is stretched between two fixed points. The tensile load at 65°F is 1250 lb. What will be the stress at 0°F? At what temperature will the stress be zero? Assume a = 6.5×10“ in / (in-°F) and E = 29 × 10° psi. %3D

Problem Solving... The cross-sectional area of the bar is 5 cm2. Use E= 70 GPa for aluminum, and E= 200 GPa for steel. Aluminum Steel Aluminum 80 kN 20 kN 30 kN 70 kN A 3 m -4 m- 5 m- - What is the elongation in segment AB (Aluminum)? * -7.8571 x10^-3 m O6.8571 x10^-3 m O -6.8571 x10^-3 m 7.8571 x10^-3 m

On a day that the temperature is 6.0°C, a concrete walk is poured in such a way that the ends of the walk are unable to move. Take Young's modulus for concrete to be 7.00 × 109 N/m² and the compressive strength to be 2.00 x 109 N/m². (The coefficient of linear expansion of concrete is 1.2 × 10-5 (°C-¹).) (a) What is the stress in the cement on a hot day of 49.0°C? N/m² (b) Does the concrete fracture? ○ Yes ○ No

A hot air balloon uses the principle of buoyancy to create lift. By making the air inside the balloon less dense then the surrounding air, the balloon is able to lift objects many times its own weight. A large hot air balloon has a maximum balloon volume of 2090 m3. a.  If the air temperature in the balloon is 54 °C, how much additional mass, in kilograms, can the balloon lift? Assume the molar mass of air is 28.97 g/mol, the air density is 1.20 kg/m3, and the air pressure is 1 atm.