Homework questions, hints please?

1. Feb 6, 2007

moshilover

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??

Last edited: Feb 6, 2007
2. Feb 6, 2007

Until you show how you got your incorrect answers, we'll hardly be able to help you.

3. Feb 6, 2007

cristo

Staff Emeritus
Well, which equations did you use?

Show your working, and it will be easier to see where you went wrong

4. Feb 7, 2007

andrevdh

... 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.