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Homework questions, hints please?

  • Thread starter moshilover
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Homework questions, hints please??!!

1. A ball is thrown upward. Its initial vertical speed is 10.4 m/s, acceleration of gravity is 9.8 m/s^2, and maximum height hmax are shown in the figure below. What is its height, hmax? Answer in units of m. Neglect: air resistance

For this one I used 3 different formulas in different ways and each answer I got was wrong when I checked it. I divided 10.4 and 9.8 and got .9423076923 for time. Then I plugged that into a distance formula of d=ViT+1/2aT^2 and got 16.55510205 which was wrong.

2.A ball is thrown upward. Its initial vertical speed is v0, acceleration of gravity is 9.8 m/s^2, and maximum height is 5.5 m, as shown in the figure below. What is its initial vertical speed, v0? Answer in units of m/s. Neglect: Air resistance

So since the initial vertical speed is v0 wouldnt the initial velocity just be 0?? And so the answer is 0??
 
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Answers and Replies

radou
Homework Helper
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Until you show how you got your incorrect answers, we'll hardly be able to help you. :rolleyes:
 
cristo
Staff Emeritus
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1. A ball is thrown upward. Its initial vertical speed is 10.4 m/s, acceleration of gravity is 9.8 m/s^2, and maximum height hmax are shown in the figure below. What is its height, hmax? Answer in units of m. Neglect: air resistance

For this one I used 3 different formulas in different ways and each answer I got was wrong when I checked it....could someone give me a hint or show me how to do this??
Well, which equations did you use?

2.A ball is thrown upward. Its initial vertical speed is v0, acceleration of gravity is 9.8 m/s^2, and maximum height is 5.5 m, as shown in the figure below. What is its initial vertical speed, v0? Answer in units of m/s. Neglect: Air resistance

This one I got 10.38267788, but I checked this one too and says its incorrect. I used the distance formula......
Show your working, and it will be easier to see where you went wrong
 
andrevdh
Homework Helper
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... I divided 10.4 and 9.8 and got .9423076923 for time ...

My calculator gives another value for this calculation. You divided 9.8 by 10.4, which gives a value with a unit of per second.
 

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