Yahoo Answers: Answers and Comments for Projectile motion question? [Physics]
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From Kit K
enUS
Thu, 20 Oct 2011 10:34:36 +0000
3
Yahoo Answers: Answers and Comments for Projectile motion question? [Physics]
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https://answers.yahoo.com/question/index?qid=20111020103436AAAlrmi
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From cardejon: The adverse sign refers back to the path of th...
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https://answers.yahoo.com/question/index?qid=20111020103436AAAlrmi
Fri, 21 Oct 2016 14:06:15 +0000
The adverse sign refers back to the path of the rigidity, this is downward. with the aid of convention, adverse speed and adverse acceleration are downward. in case you place g as advantageous, then a projectile released upwards could have adverse speed, which does no longer make intuitive sense.

From PCon: If the ball has a horizontal velocity of 25m/s...
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https://answers.yahoo.com/question/index?qid=20111020103436AAAlrmi
Thu, 20 Oct 2011 10:50:12 +0000
If the ball has a horizontal velocity of 25m/s and travels a horizontal distance of 50m, then you can find the time taken, which is what you have done which is correctly 2 seconds.
Now next you must consider the vertical components of the projectiles motion and assume that the positive direction is pointing down, just to make the calculation a little easier...
What do you known:
 acceleration of freefall = a = 9.8m/s^2
 time taken = t = 2s
 initial vertical velocity = 0m/s
The initial vertical velocity is zero because it says the ball was thrown horizontally. If the ball was thrown horizontally, initially it would have had a vertical component of zero.
 height at which the ball was thrown = s = ?m
Now using the constant acceleration equations, you can solve the problem because you have one unknown quantity, and the best equation to use is:
s = ut + 0.5at^2
since u = 0m/s...
s = 0.5at^2
plugging in the numbers you know should give you an answer of 19.62m.
This answer should be correct, go through it yourself to verify that what I have done is correct though.