Calculating the Speed and Acceleration of Jillian's Engagement Ring

[aznriceboiz5]

Jillian angrily throws her engagement ring straight up from the roof of a building, a height 11.5 above the ground, with an initial speed of 4.95 . You may ignore air resistance.

For the motion from her hand to the ground, what is the magnitude of the average velocity of the ring?

Isn't avg velocity = x2-x1/t2-t1? if they don't give you t do you have to figure it out? I did but i still got it wrong. It looks to simple from the calculations I have been making. This is my first physics class and its hard

For the motion from her hand to the ground, what is the magnitude of the average acceleration of the ring?
same with this one


In how many seconds after being thrown does the ring strike the ground?


What is the speed of the ring just before it strikes the ground?


thanks for the help everyone

 

[curly_ebhc]

You have a good start

You have the avg. velocity part right and you need to solve for time.

Hints.
1. What is the avg. acceleration (this is the key to the problem)
2. You can use the 4 eqns. of motion to solve any other question you asked.
3. Be very careful with negative signs. Make up positive and down negative. If you don't your math will be wacked out.
4. When solving for time you will get 2 solutions. ( You may need to use quatdratic equation.) Just ignore the negative time it is not physicaly relevant.

I hope this is a good start.

 

[aznriceboiz5]

Thanks curly