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Homework Help: A couple questions,

  1. Sep 18, 2008 #1
    1. The problem statement, all variables and given/known data

    Question 1:During a walk on the Moon, an astronaut accidentally drops his camera over a 13.8 m cliff. It leaves his hands with zero speed, and after 2.2 s it has attained a velocity of 3.3 m/s downward. How far has the camera fallen after 3.9 s?

    Question 2: A stone is launched straight up by a slingshot. Its initial speed is 18.8 m/s and the stone is 1.7 m above the ground when launched. (a) How high above the ground does the stone rise? (b) How much time elapses before the stone hits the ground?

    Question 3:A 1.6-kg ball tied to a string fixed to the ceiling is pulled to one side by a force to an angle of 34.2° from the ceiling. The force is pulling the ball directly right.
    Just before the ball is released and allowed to swing back and forth, (a) how large is the force that is holding the ball in position and (b) what is the tension in the string?

    2. Relevant equations

    question 1: I do believe i use basic equation of vy = v0y ayt and y = y0 + v0yt + 1/2 ayt2

    Question 2: Same as Question 1..

    Question 3: Tension = ma + mg

    3. The attempt at a solution

    Question 1: I tried to get the total distance it went for the first 2.2 seconds and tried to get the rest using the 3.9 seconds, but apparently its wrong.

    Question 2: I tried to get time of how long it is in the air and used that to get the distance, but i keep getting wrong answers..

    Quesiton3 : Im actually kinda clueless on question 3 so help would be appreciated.
  2. jcsd
  3. Sep 18, 2008 #2


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    What is the acceleration from moon's gravity given by the information in the problem. Then once you have acceleration you have distance from 1/2 a t2
  4. Sep 18, 2008 #3
    Acutally not sure as its not given
  5. Sep 18, 2008 #4


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    Calculate it then.
  6. Sep 18, 2008 #5
    Sorry, but how do i get the gravity for the moon? Im checking my physic book, but i cant get some value to get the graivty.
  7. Sep 18, 2008 #6


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    The information the problem gives you allows you to calculate it.
  8. Sep 18, 2008 #7
    I dont see how i can calculate it with the information i have
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