Recent content by kepler

That was my initial guess :) Thanks, Kepler

Hi, Just a stupid doubt...when the moon is in FIRST QUARTER or LAST QUARTER, their angular separation is of 90 degrees; question: is it the TRUE angular separation or is it the difference of ecliptic longitudes? Kind regards, Kepler

Hi, Supose I drop a body of 7 Kg from a height of 2 meters. Is the impact energy equal to: E = m * g * h = 7 * 9.81 * 2 = 137,34 Joules ? And if it is, is the kinetic energy equal to this ammount? Kind regards, Kepler

Hi, If we were to change the Earth's orbit, what force should we apply and in what direction? Shoud we go against G.(M_Earth + M_Sun) / distance^2 or against the centripetal force, M_Earth.v^2/distance? I've calculated this last one and I got the result: 3,542396634E+22 Newtons Is...

Regarding the impact being equal to the kinetic energy ( m . g . h ), I'm not sure... if a body of 10 Kg falls from the height of 200 meters it will have the same KE of another body of 50 Kg falling from 40 meters. Which would you prefer to be hit with ? Since accelaration ' g ' is pratically...

... Ok guys... Forget it's an astronaut. Forget it's Deimos. Let's bring the problem "home". If a body ( perfect ball ) with a mass ' m ' Kg falls from ' h ' meters high ( initial velocity = 0) hitting the Earth's ground, what will it be the Force of the Impact in Newtons? We know: 1)...

Ok... so, the energy, in Joules, is well calculated, right? Since it's equal to mgh. As for the force, I don't understand very well what you mean. I know the velocity is sqrt(3g) and the fall time is sqrt(3/g). So according to you (sqrt(3g))^2-0=2ah 3g=2*a*1.5 g = a So F = mg...

Hi, If an astronaut of 75 Kg of mass gives a jump of 1.5 meters in the air and hit the ground of the martian satellite Deimos then: 1) what will be the force of the impact in Newtons? 2) What will be the energy of the impact in Joules? 3) Will Deimos move? I think we must first...

I tryed to delete it...

Hi, If at a particular time, I have the r distance from the Sun to Earth, the value of the velocity of Earth, and the angle between the velocity vector and the r vector, how can I calculate the force that Earth has regarding the tangent? Suppose I wanted to go againts the movement of the...

It doesn't; England does. Only by chance the meridian of Greenwich, to which UTC refers, is located there. UTC, the previous GMT, is a time scale for "ruling" correspondences between the solar day in all locations on Earth. Even so, it's not accurate in astronomical terms; we take a day as the...

well... Forgive me to disagree. First I was only giving an example in one context. But let's supose we go far in the past; one hour, in astronomy, is a century - just like 10^(-6) is huge in curve fitting in Math. Have you ever seen how much the moon "moves itself" in one hour? 5 mihutes are...

yes, but... I agree completely - but the problem is that the right construction of constants and variants decreases as we go into the past. Look at the example of the babylonian calendar in the Jesus epoch; it depended of witnesses of one phase of the Moon that traveled hours or days, by foot...

Hi, A peculiar situation ( every time DST ends ): DST ( = UTC+1 ) ended, for example, in 1979 - in Portugal - the 30th September at 2 AM - it lasted until 1h59m59s AM and, one second later, corresponded automatically to 1 AM ( UTC 0 ). Ok, that's fair. But now, let's supose that we know of an...

...oopsss... Dear Tony, the problem was that I had initial data incorrect - the routine does work. Complemented with mine, everything's ok - but it doesn't corresponds to the JPL data. Now I have a doubt ( the final one I think ): in the system that you computed, with that Mu value (...