The first active volcano observed outside the Earth was discovered in 1979 on Io, one of the moons of Jupiter. The volcano was observed to be ejecting material to a height of about 2.00x10^5m. Given that the acceleration of gravity on Io is 1.80m/s^2, find the initial velocity of the ejected material.

I can't give you the answer to you... that would not teach you much... I will give you a quick method though.

When ever something falls, it is accelerated my gravity.

When ever something raises up, its speed is accelerated by gravity negatively.

Similarly when an object reaches its peak and begins to fall it will accelerate at the same rate it de-accelerated on the way up.

Also at its peak, it will have the same potential as if you were to drop it from there.

If you still don't get it... keep asking questions.

But I don't understand the equations, since I only have one variable

You know that v^2 = u^2 +2as

At the maximum height, the final velocity is zero. You have the acceleration a, (it's negative relative to the initial velocity) and you have the distance s. Solve for u, the initial velocity.

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Ok, you said you don't understand the equations, which one do you know about?

Use the equation for a falling object. The distance is the height. The acceleration is 1.80m/s/s. You are trying to find speed.

u=sqrt9.81*200000*2=1981, but that's wrong

Sorry I entered the wrong acceleration, thanks guys that worked, I got it now.

ryty, we need to know what you don't understand! You sais you didn't understand something in the equations. What was that? :confused:

ryty, we need to know what you don't understand! You sais you didn't understand something in the equations. What was that? :confused: