Question

Can someone help me with these two? Pretty sure I did them wrong. Thanks

your diagram? 4. An escalator is 30.0 meters long and slants 30 degrees relative to the horizontal. If it moves at 1.00 m/s, at what rate does it do work in lifting a 50.0 kg man from the bottom to the top of the escalator? T y 20 Did you draw free-body diagram for this problem? If so, why did you draw a diagram? Did you use the diagram to solve the problem? How? What did you include in your diagram?

Answer 1

F = mg = 50 times 9.8 upward Rate of work done = F vector middot V vector = FV cos theta theta = angle between F vector and V vector {here theta = 60 degree} P = 50 times 9.8 times 1 times cos 60 degree P = 50 times 9.8 times 1/2 J/dec P = 245 J/dec \r\n h = l sin 37 degree = 3l/5 using conservation of energy mgh = 1/2 kx^2 {potential energy of block} {spring energy} 1 times 9.8 times 3l/5 = 1/2 times 200 (0.2)^2 5.88 l = 4 l = 0.68 m so it slides = 0.68 m