When discussing valve train components, tech a says stamped rocker arms are very strong and may be used in high-horsepower engines. tech b says forged rocker arms are used in high-torque, high-horsepower applications. who is correct?

The lid of a pressure cooker forms a nearly airtight seal. steam builds up pressure and increases temperature within the pressure cooker so that food cooks faster than it does in an ordinary pot. the system is defined as the pressure cooker and the water and steam within it. if 2.0 g of water is sealed in a pressure cooker and then vaporized by heating, and 5127 j must be added as heat to completely vaporize the water, what is the change in the system’s internal energy? answer in units of j.