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Homework Help: I need help on my physics homework!

  1. Sep 4, 2008 #1
    hey, im taking physics 1 and i have homework, but im not sure where to start or how to do the problems!! my book is NOT helpful, so if anyone can help me it will be greatly appreiciated!

    1)A ball is thrown upward from the ground with an initial speed of 23.3 m/s; at the same instant, a ball is dropped from a building 13.4 m high. After how long will the balls be at the same height?

    2)A model rocket is launched straight upward with an initial speed of 49.6 m/s. It accelerates with a constant upward acceleration of 2.01 m/s2 until its engines stop at an altitude of 170 m. What is the maximum height reached by the rocket?How long after lift off does the rocket reach its maximum height? How long is the rocket in the air?

    3)A startled armadillo leaps upward rising 0.444 m in 0.230 s. What was its initial speed?What is its speed at this height?How much higher does it go?

    4)A particle moves along the x axis according to the equation
    x = 47 t + 8t2

    (where t is in seconds and x is in meters). Calculate the average velocity of the particle during the first 3.0 s of its motion.Calculate the instantaneous velocity of the particle at t = 3.0 s.Calculate the instantaneous acceleration of the particle at t = 3.0 s.

    If anyone can help with ANY of these, it would be a huge help!
  2. jcsd
  3. Sep 4, 2008 #2


    User Avatar
    Homework Helper

    Welcome to PF.

    I'm sure your book has formulas that cover the material. Which ones do you think applies? People will help you sort it out if you have made an effort, but alas doing your work for you is not in the cards.
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