Launching a rocket from the Earth's surface

    There are 3 rockets show in the animation - we are assuming they are given a "punch it" speed (i.e. all their KE in one instant ... then they 'coast') - that's not how our rockets do that (and the Astronauts are happy about that!).

The RED one is the rocket given the Escape speed for the Earth - thus it will keep going .. the other two are given the speeds of 0.9 and 0.8 of the escape speed ... they don't go very far at all, huh? That gravity well of the Earth is steep! (For this animation, the Gravitational Potential Energy at the Earth's surface has been scaled to 100 units.)

Notice also that the two rockets that fall back seem to bury themselves into the center of the Earth ... there is a little timing problem with my code for the Physlet ... I'm working on that! Again, we hope the rockets don't normally do that!

Below the animation is a graph showing the gravitational potential well, and the three rockets "rising" out of the well. Notice that the one that escapes has enough Kinetic Energy to overcome the gravitational energy that trapped it at the surface ... the others did not have enough KE, so they dropped back to the Earth.