A sign (mass 2300kg ) hangs from the end of a vertical steel girder with a cross-sectional area of 0.014m2 . Ignore the mass of the girder itself. The elastic modulus for steel is 2.0×1011N/m2. Part A What is the stress within the girder? Express your answer to two significant figures and include the appropriate units. stress = Part B What is the strain on the girder? Express your answer to two significant figures. strain = Part C If the girder is 6.30m long, how much is it lengthened? Express your answer to two significant figures and include the appropriate units. Δℓ =

A seesaw made of a plank of mass 10.0 kg and length 4.00 m is balanced on a fulcrum 2.00 m from one end of the plank. A 32.0-kg mass rests on the end of the plank 1.5 m from fulcrum. where should 64kg man sit on the fulcrum remains balanced?

•Describe why pressure and temperature play a critical role in the stability of gas hydrates. Assess the potential for methane hydrate to be harvested as an energy source. Include a discussion of where methane hydrate deposits predominantly occur, challenges in locating and harvesting these resources, and any special environmental considerations.•Describe the differences and similarities between temperature and heat. Analyze how heat transfer occurs during the processes of conduction and convection. Provide an example of where each occurs in natural physical systems.•Describe how an electric current is generated and transported. Assess the current state of our national grid in the United States, as well as any challenges in updating this grid.•From the first and second e-Activities, describe how the Earth's magnetic field is generated, and how it has changed throughout Earth's history. Analyze how a magnetic reversal might impact human activities on Earth.