What is the latest invention?

Lou's Latest invention, Aimed at urban dog owners...what was the work done on the dog?

• Lou’s latest invention, aimed at urban dog owners, is the X-R-Leash. It is made of a rubber-like material that exerts a force Fx=(−8.3N/m)x−(31N/m2)x2whenit is stretched a distance x. The ad claims, “You’ll never go back to your old dog leash after you’ve had the thrill of an X-R-Leash ex- perience. And you’ll see a new look of respect in the eyes of your proud pooch.” Find the work done on a dog by the leash if the person remains stationary, and the dog bounds off, stretching the X-R-Leash from x = 0 m to x = 10 m. Answer in units of kJ.

• Answer:

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