How can you define the need to build an exciting, but safe, roller coaster as an engineering design problem?

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented

Technician a says that in a worm gear steering system, most excessive steering free play is usually found in the gearbox. technician b says that in a rack-and-pinion steering system, excessive free play can be found in the bushings. who is correct?

An electrical kettle is made out of stainless steel,weighs two pounds (when empty) with a heating element that consumes 2 kw of electricity. assuming that the water and the kettle are at the same uniform temperature at any moment of time, calculate the shortest possible time to bring 2 quarts of water from room temperature to the onset of boiling.