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Thread: Physics Help

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    Physics Help

    A ball thrown from 2 meters above the ground with a velocity of 6.8m/s at an angle of 60 degrees above the horizontal lands in a basket 2.3 meters away.

    a) What is the height of the basket?
    b)With what velocity (magnitude and angle) does the ball land in the basket? Neglect air resistance.

    I just need help getting started, not looking for an answer. I think I'm just over thinking it because the 60 degrees is thrown in there.

    Thanks in advance!



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    Re: Physics Help

    Quote Originally Posted by TitanClone View Post
    A ball thrown from 2 meters above the ground with a velocity of 6.8m/s at an angle of 60 degrees above the horizontal lands in a basket 2.3 meters away.

    a) What is the height of the basket?
    b)With what velocity (magnitude and angle) does the ball land in the basket? Neglect air resistance.

    I just need help getting started, not looking for an answer. I think I'm just over thinking it because the 60 degrees is thrown in there.

    Thanks in advance!
    Separate your initial velocity into horizontal and vertical components (cosine and sine, respectively), and then you have constant-velocity in the horizontal direction and constant acceleration (gravity, acting downward) in the vertical direction.

    EDIT: from this you can find your ending velocities and use the tangent function to find the angle.


    Last edited by iahawkhunter; 01-24-2011 at 08:13 PM.
    Quote Originally Posted by im4cyclones View Post
    [Anything] is easy if you are content to suck at it.

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    Re: Physics Help

    Quote Originally Posted by iahawkhunter View Post
    Separate your initial velocity into horizontal and vertical components (cosine and sine, respectively), and then you have constant-velocity in the horizontal direction and constant acceleration (gravity, acting downward) in the vertical direction.

    EDIT: from this you can find your ending velocities and use the tangent function to find the angle.
    Thanks!

    Took me 2 minutes after staring at it for like 20.



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    Re: Physics Help

    Unless it involves an airplane taking off from a treadmill we can't help you here.



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    Re: Physics Help

    Quote Originally Posted by TitanClone View Post
    Thanks!

    Took me 2 minutes after staring at it for like 20.
    No problem. That's a "standard" problem that's easy, but looks intimidating at first.


    Quote Originally Posted by im4cyclones View Post
    [Anything] is easy if you are content to suck at it.

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    Re: Physics Help

    Quote Originally Posted by jtdoyle1 View Post
    Unless it involves an airplane taking off from a treadmill we can't help you here.
    Will the airplane take off? Or will it not? Are the bearings in the wheel frictionless? Is it an ideal plane?

    That thread was priceless...I only wish I was around when it was written!



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    Re: Physics Help

    Quote Originally Posted by CtownCyclone View Post
    Will the airplane take off? Or will it not? Are the bearings in the wheel frictionless? Is it an ideal plane?

    That thread was priceless...I only wish I was around when it was written!
    Time to bring it back to rethink the solution.


    Let my Fred's Posse Ride: Georges, Naz, Hogue, Bryce, Nader, Monte, Matt, and McKay.

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    Re: Physics Help

    Quote Originally Posted by CtownCyclone View Post
    Will the airplane take off? Or will it not? Are the bearings in the wheel frictionless? Is it an ideal plane?

    That thread was priceless...I only wish I was around when it was written!
    Did anyone ask if the airplane was a Harrier or an Osprey?



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    Re: Physics Help

    Quote Originally Posted by Wesley View Post
    Time to bring it back to rethink the solution.
    http://www.cyclonefanatic.com/forum/...treadmill.html

    Enjoy.



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    Re: Physics Help

    I'm sure this problem is easy; I just can't find the correct formula to use. Anyone know it?

    In November 2007, astronaut Pam Melroy, history’s second woman space
    shuttle commander, flew the space shuttle Discovery to the International
    Space Station to continue construction. To undock from the space station,
    Commander Melroy released hooks holding the two spacecraft together and
    the 76,700 kg shuttle pushed away from the space station with the aid of 4 large
    springs. a) If the 232,700 kg space station moved back at a speed of 0.50 m/s,
    how fast and in what direction did the space shuttle move



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    Re: Physics Help

    Quote Originally Posted by JUKEBOX View Post
    I'm sure this problem is easy; I just can't find the correct formula to use. Anyone know it?

    In November 2007, astronaut Pam Melroy, history’s second woman space
    shuttle commander, flew the space shuttle Discovery to the International
    Space Station to continue construction. To undock from the space station,
    Commander Melroy released hooks holding the two spacecraft together and
    the 76,700 kg shuttle pushed away from the space station with the aid of 4 large
    springs. a) If the 232,700 kg space station moved back at a speed of 0.50 m/s,
    how fast and in what direction did the space shuttle move
    Momentum must be conserved, so the space station's momentum in one direction must be countered by the shuttle's momentum in the other (akin to equal and opposite forces). Since momentum is mass times velocity:

    (232700)*(0.5) + (76700)*(v) = 0

    The two terms sum to 0 because there is no initial relative velocity between the shuttle and the station. This will also give the shuttle velocity, v, as a negative number which will reflect the fact that the shuttle is moving in the opposite direction of the station.


    Quote Originally Posted by im4cyclones View Post
    [Anything] is easy if you are content to suck at it.

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    Re: Physics Help

    Quote Originally Posted by iahawkhunter View Post
    Momentum must be conserved, so the space station's momentum in one direction must be countered by the shuttle's momentum in the other (akin to equal and opposite forces). Since momentum is mass times velocity:

    (232700)*(0.5) + (76700)*(v) = 0

    The two terms sum to 0 because there is no initial relative velocity between the shuttle and the station. This will also give the shuttle velocity, v, as a negative number which will reflect the fact that the shuttle is moving in the opposite direction of the station.
    This is what I thought, but they have a different answer on this website.
    http://www.chsdarkmatter.com/hps10.pdf


    I get 1.517 m/s, but they have 2.52 m/s.



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    Re: Physics Help

    I freaking hated 221. Thank God for graphing calculators with memory to store formulas (yeah, I cheated on some tests).



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    Re: Physics Help

    Quote Originally Posted by JUKEBOX View Post
    This is what I thought, but they have a different answer on this website.
    http://www.chsdarkmatter.com/hps10.pdf


    I get 1.517 m/s, but they have 2.52 m/s.
    Crap. After some internet searching here's what I've found:

    Astronaur Pam Melroy flew the space shuttle Discovery to the International Space Station to complete? - Yahoo! Answers (same approach as I said above, but with different numbers)

    Note that the linked problem asks for the relative velocity between the shuttle and station. If we do that here, you get 2.02 m/s (0.5 + 1.52), which makes up half the difference between your answer and the provided answer. I'm not sure where the remaining 0.5 m/s is coming from, and since the question just asks for the shuttle velocity I feel like the relative velocity between them is irrelevant.


    Quote Originally Posted by im4cyclones View Post
    [Anything] is easy if you are content to suck at it.

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    Re: Physics Help

    i think the answer comes out to going 75/75 on free throws...or maybe im getting it confused with something else



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