0.3 Work, Energy, and Power

Last updated 3 months ago

3 questions

Our textbook for this summer assignment will be OpenStax College Physics for AP Courses. Please review Chapter 7 in the book (mainly 7.2-7.7) and then do Problems 26, 27, and 32 in the "Problems and Exercises" section for Chapter 7. Put your answers below. If you format your answers correctly, formative will auto-grade when you submit the assignment. Include units on all answers, with a space before the unit. For instance, "27.4 km/s". Express large and small numbers in scientific notation with the letter e: "4.5e13 kg".

Required

27.Using energy considerations and assuming negligible air resistance, show that a rock thrown from a bridge 20.0 m above water with an initial speed of 15.0 m/s strikes the water with a speed of 24.8 m/s independent of the direction thrown.

Required

0.3 Work, Energy, and Power

Last updated 3 months ago

3 questions

Our textbook for this summer assignment will be OpenStax College Physics for AP Courses. Please review Chapter 7 in the book (mainly 7.2-7.7) and then do Problems 26, 27, and 32 in the "Problems and Exercises" section for Chapter 7. Put your answers below. If you format your answers correctly, formative will auto-grade when you submit the assignment. Include units on all answers, with a space before the unit. For instance, "27.4 km/s". Express large and small numbers in scientific notation with the letter e: "4.5e13 kg".

Required

26.Using values from Table 7.1, how many DNA molecules could be broken by the energy carried by a single electron in the beam of an old-fashioned TV tube? (These electrons were not dangerous in themselves, but they did create dangerous x rays. Later model tube TVs had shielding that absorbed x rays before they escaped and exposed viewers.)

Required

27.Using energy considerations and assuming negligible air resistance, show that a rock thrown from a bridge 20.0 m above water with an initial speed of 15.0 m/s strikes the water with a speed of 24.8 m/s independent of the direction thrown.

Required

32.A person in good physical condition can put out 100 W of useful power for several hours at a stretch, perhaps by pedaling a mechanism that drives an electric generator. Neglecting any problems of generator efficiency and practical considerations such as resting time: (b) How many people would it take to replace a large electric power plant that generates 800 MW?