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Physics, Projectile Motion Help?

Ive been absent from school for the entire week and I don't know how to do these.

http://i.imgur.com/GTcEMrI.png

Could you help me do some of these? or explain how to do some? This is due in 45 mins. Ive spent past 2 hours trying to figure out how to do this and this is so frustrating!

Any question that you help on would be highly appreciated.

Thanks!

1 Answer

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  • 7 years ago
    Favorite Answer

      Vix = (29.8) • cos(24º)  ...  horizontal component of the initial velocity

      Viy = (29.8) • sin(24º)  ...  vertical component of the initial velocity

    Since air resistance (friction) is neglected, the horizontal component of the

    initial velocity is CONSTANT:  Vix = Vx

    The horizontal displacement given is:  ∆x = 67.2724 m

    so the time of flight ( T ) is found using the horizontal motion equation:

        ∆x = (Vix) • T   ...   distance = speed • time

      67.2724 = (29.8) • cos(24º) • T

        T = 2.47 sec  ...  time of flight  ◀◀

    ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

    At the peak height, the vertical component of the velocity is ZERO.

    Using the standard energy-motion physics equation:

        (Vғy)²  –  (Viy)² = 2 • g • h   ...  final vertical velocity  =  Vғy   and   height  =  h

        (0)²  –  ((29.8) • sin(24º))² = 2 • (- 9.81) • h   ...  where: Vғy = 0  at the peak height

        h = 7.49 meters  ...  peak height

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