Homework questions, hints please?

[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 wouldn't the initial velocity just be 0?? And so the answer is 0??

 

[radou]

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

 

[cristo]

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]

... 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.