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A block rests on a table. Then the block is pushed by a spring and slides across the table until it falls to the ground. The mass of the block is $1.30\text{ kg}$, the spring constant $550\text{ N/m}$ and the spring has been compressed by $0.11\text{ m}$. The block slides a distance of $67\text{ cm}$ across the table,which has a height of $76\text{ cm}$. The coefficient of kinetic friction between block and table is $0.16$. What speed will the block have when it lands on the ground and at which angle will it hit the ground?

I found the sliding velocity after the block leaves the spring and it is $$ v=\ x \sqrt{k/m}$$ where $x$ is the length of the compression of the spring. I am pretty sure that Work Energy theorem,or conservation of energy should be applied here, but I am not sure how.

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Can you figure out how fast the block will be moving when it hits the edge of the table? What direction will it be moving in right when it leaves the table? – Jerry Schirmer Oct 29 '12 at 15:30
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Hi Pilot, and welcome to Physics Stack Exchange! As our homework policy says, we don't give complete answers to homework-like questions, but it's fine to have someone explain how energy conservation applies (or doesn't, if that is the case) to this problem. I've edited your question accordingly; please take a look at the edits and see if they reflect what you want to ask. – David Zaslavsky♦ Oct 29 '12 at 15:50
Your calculation of the sliding velocity did not take into account friction with the table. – Jaime Oct 29 '12 at 16:36

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I think a good way to start would be to look at what velocity the block will leave the table (that's velocity, and not speed). Once you have that, you know how high the block is above the ground. So with a velocity and a height, the rest of the question follows.

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Do we use straight line motion for that in that case where do we use elastic energy? Or de we use conservation of energy ,in that case where do make use of the distance that block slides is 0.67m? – Pilot Oct 29 '12 at 16:06
I think we can assume that the motion is 2D. So you know the energy stored in the spring, and the coefficient of friction. So you can calculate the velocity at which the block will leave the surface. From newton's law given an initial velocity and an acceleration (gravity) you can calculate the final velocity. – Kitchi Oct 29 '12 at 16:29

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