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Homework Help: HELP w/ Kinematics Problems?

  1. Sep 20, 2009 #1
    HELP w/ Kinematics Problems??

    1. The problem statement, all variables and given/known data
    a) A baseball is thrown horizontally at 45m/s. The ball slows down at a rate of 5m/s^2. How long is the ball in the air before coming to rest?

    b) A pile driver drops from a height of 35m before landing on a piling. What is the speed of the driver when it hit the piling?

    c)A meteor falls from the sky to Earth. The meteor already had an initial velocity downward when it was spotted. If it hit the Earth at 335m/s after being seen for 30 seconds, then what was the initial velocity of the meteor?

    d) A car started from a rest and accelerated at 9.54m/s^2 for 6.5 seconds. How much distance was covered by the car?

    2. Relevant equations
    a) a = change in velocity/time
    b) speed = d/t
    c) final velocity = initial velocity + (acceleration*time)
    d) a & s

    3. The attempt at a solution
    a) a = 5m/s^2, v = 45m/s...now what??
    b) speed = 35/t....NOW WHAT???
    c) 335 = vi + (a*30)...now what?? is this even right?
    d) (6.5)2 is 42.5s2...so is 42.5m the answer??

    Physics completely baffles me. I'm not a math person at all. Any or all help would be GREATLY appreciated, thanks so much...
  2. jcsd
  3. Sep 20, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi dagitt! Welcome to PF! :wink:

    For each question, use the standard constant acceleration equations (using g as the acceleration for questions b) and c) ) :smile:
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