What is the gravitational potential energy of a 20kg object at a height of 50 m?

Ablock of steel has a density of 0.29lbs per cubic inch. if the block has dimensions of 1 inch by 1 inch by 3 inches, what is its weight? a. 0.29lbs b. 0.58lbs c. 0.87lbs d. 1lbs

15. give an example for some particles or waves that are moving faster than light in everyday life 16. what is a laser? 17. what is an oscilloscope? 18. what does it means practically that nothing is faster than light in vacuum? 19. what is vacuum?

Awater slide of length l has a vertical drop of h. abby's mass is m. an average friction force of magnitude f opposes her motion. she starts down the slide at initial speed vi. use work-energy ideas to develop an expression for her speed at the bottom of the slide. then evaluate your result using unit analysis and limiting case analysis. express your answer in terms of the variables h, m, l, vi, f and appropriate constants. vf v f