(adsbygoogle = window.adsbygoogle || []).push({}); An object is released from rest at an altitude h above the surface of the Earth.

a) Show that its speed at a distance r from Earth's center, where [tex]R_{E}\leq r\leq R_{E}+h[/tex], is given by

[tex]v=\sqrt{2GM_{E}(\frac{1}{r}-\frac{1}{R_{E}+h})}[/tex]

b)Assume the release altitude is 500km. Perform the integral

[tex]\Delta t=\int^{f}_{i} dt=\int^{f}_{i} -\frac{dr}{v}[/tex]

to find the time of fall as the object moves from the release point to the Earth's surface. The negative sign appears because the object is moving opposite to the radial direction, so its speed is

[tex]v= -\frac{dr}{dt}[/tex]. Perform the integral numerically.

I am at a total loss with this one. It is my final physics problem ever! I am done with physics! (Computer Science major) Please, help. My head is about to explode.

Thank you.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Universal gravity problem help needed

**Physics Forums | Science Articles, Homework Help, Discussion**