Recent content by WillParadigm

  1. W

    Unveiled: A Revolutionary Safety Air-Brake for Elevators

    not really, I'm still lost on this problem... gah, so much work for just one problem... UGH.
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    Unveiled: A Revolutionary Safety Air-Brake for Elevators

    ok, I somewhat understand the problem a little better, but I did something wrong... a=g=9.8 since acceleration is constant? because the cable just snaps, so it's just gravity, and a can be set equal to a=Force/mass and mass is equal to weight/g which in this case, then 700 lbs/9.8 m/s^2...
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    Unveiled: A Revolutionary Safety Air-Brake for Elevators

    An engineer claims to have a new kind of "safety" air-brake for elevators. If the cable should snap, a patented velocity-sensor turns on the brakes once the elevator hits 40 mph. The brakes are powerful enough to stop a 700 lb elevator in 1/20 of a second. How much force do the brakes exert...
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    Estimate how fast he should be moving

    are you a physics professor/major? because you should be... =) thank you very much, that makes 100% sense now.
  5. W

    Estimate how fast he should be moving

    ok, I can understand that part for finding time, superman's final height g = 9.8 m/s² and upward velocity is negative, since the gravitational acceleration, which acts downward, is always positive. so when superman reaches his maximum height, his velocity should be zero. right? So, vf = 0...
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    Estimate how fast he should be moving

    ok reedited, so I know what I'm looking for, but the question is, how do I determine how to find them, what equation am I missing?
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    Estimate how fast he should be moving

    Kinematics Problem. How do I get T to solve for V(i). PLEASE HELP 9.Superman is supposed to leap tall buildings in a single bound. Suppose that he obeys the normal laws of physics in this feat. Estimate how fast he should be moving when he leaves the ground so that he just clears the top of...
  8. W

    X versus t graph, simple kinematics?

    but that y intercept equation, I don't see how it helps, it just gives me an equation for a line I already saw, but not even the whole line...
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    X versus t graph, simple kinematics?

    couldn't the final velocity be any point along the line in the above graph? see that's what's confusing me the most, that there aren't any concrete numbers that I can see to use I mean, for the first part of the graph, I can see yes, the equation should be y=1/2x+15 because the slope is...
  10. W

    X versus t graph, simple kinematics?

    so it's (10-15)/(120-0) to get acceleration of -1/24 and I just graph 15x + (1/2)(-1/24)x^2? all I got was a straight line
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    X versus t graph, simple kinematics?

    wait, now you lost me... how does that help me graph something in x intervals of Time t (s) and y intervals of Position x (m)
  12. W

    X versus t graph, simple kinematics?

    the book I have does have a drawing of a x versus t graph, but it derives it from already having acceleration... and used the equation x=Initial Velocity x Time + 1/2 x Acceleration x Time^2
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    X versus t graph, simple kinematics?

    the question was this exactly... "7 Chapter 2, Question 22,and plot an x vs t graph of the motion." so I mean, the directions aren't that helpful, plot an x vs t graph of the motion
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    X versus t graph, simple kinematics?

    that's all I can get, just that it curves up from 0 but then I know there are other dips and peaks, and a level off since the velocity goes to zero, but I don't know how to draw it
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    X versus t graph, simple kinematics?

    yeahh, some of us were confused too, and did what the instructions on the pic show, but we're supposed to graph an x versus t graph of that picture showing the velocity, so it looks somewhat like an exponential growth graph...
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