(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A ball is thrown straight upward and returns

to the thrower’s hand after 4 s in the air. A

second ball is thrown at an angle of 67◦ with

the horizontal.

The acceleration of gravity is 9.8 m/s2 .

At what speed must the second ball be

thrown so that it reaches the same height as

the one thrown vertically? Answer in units of

m/s.

3. The attempt at a solution

*****I've been working on this problem for a few days. Here's what I have so far:

This is a 2-d question. First I need to find the maximum height of the first ball (thrown straight up) then I can plug that into the second ball's equations and find the Vo(x) of the second ball.

**Will the ball that's being thrown straight up have it's maximum height at 2s (half way between the total time?)

So I would have Y=0 + 0(1)+ (+)4.9(1^2).

Then Height would be +4.9? I think that gravity COULD be + because the ball is going up...but I don't know if that even makes sense.

Then I would put the Y into my second ball's equations:

1.) Y EQN: 4.9=0+Vo(y)sin(67)(t)+4.9(t^2)

2.) X EQN: x=0 + Vo(x)cos(67)(t)+ 0

3.) Vy EQN: 0=Vo(y) + -9.8(t)

4.) Vx EQN: Vx=Vo(x) + 0

**Substitute and solve for t: t=.___s

**Plug t into X EQN: x=Vo(x)cos(37)(.__s)

Now I am missing x and the magnitude.

I really don't know what to do with this problem. Any help is greatly appreciated!! Thank you! :)

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# Homework Help: Max height-2 balls-1 straight up-the other horizontal at an angle? yikes!

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