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

I have been given this example with the following questions:

1. Two rocks are thrown off of a cliff with the same initial speed, v. The first rock is launched with at an angle Ө directed below the horizontal as shown below as 1, while the second rock is launched above at the same angle.

a. Predict how the final speeds of each rock compare just before they strike the water. Provide a brief explanation justifying your prediction.

b. Measurements are taken and it turns out that both rocks strike the water below at precisely the identical speed. Justify using a conservation of energy argument. Use equations to aid your explanation.

c. Justify using a kinematics argument (projectile motion). The diagram below might help your explanation.

( I attached the two diagrams provided)

2. Relevant equations

This is where I am getting messed up... The unit that this question belongs to is in the Work, energy, power, and efficiency portion of my course work.... I am under the impression that this is a kinematics question... I can't seem to see how this fits into Work, energy, power or efficiency. As none of these things are even mentioned.

3. The attempt at a solution

a. Predict how the final speeds of each rock compare just before they strike the water. Provide a brief explanation justifying your prediction.

I do know that they will strike the water at the same time, I am just unsure how to justify this in terms of work, energy, power, or efficiency.

Thats about as far as I've gotten, I have been staring at it for ever and I just cant seem to make it click... any explanation would be helpful

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# Homework Help: Final velocity of a rock and how it compares to work

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