I've got a few questions. I'll show my work but I'm struggling and need to turn in this homework by midnight :(
1) Calculate g (the acceleration due to gravity) for the space shuttle’s orbit, 200 km above the Earth’s surface.
M= 5.98x10^24kg (given on our constants sheet). G= 6.67x10^-11N.
g=GM/r^2. ((6.67x10^-11)(5.98x10^24))/(6.37x10^6= 9.8298...
2) What is the change in the force of gravity between two planets when the distance between them becomes 10 times smaller? (Does the force increase or decrease? By what factor?)
Is this the inverse square law? I did 1/(1/10)^2= 100 increase but I don't know that I did this right.
3) Rank the average gravitational forces from greatest to least between the
a. Sun and Mars
b. Sun and the Moon
c. Sun and the Earth
To be honest I'm completely lost on how to do this one at all.
4) We often neglect the gravitational effects within an atom. Calculate and compare the gravitational and electrical forces between an electron and a proton separated by 10-10 m.
I also don't even know where to start on this one. I'm so confused.
5) Measurements show that there is an electric field surrounding the Earth. Its magnitude is about 100 N/C at the Earth’s surface, and it points inward toward the Earth’s center. Based on this information, is the Earth positively or negatively charged?
Since it states that it "points inward toward the Earth's center" I'm guessing that the Earth is negatively charged? Or is it positive because the electric field is pointing down (negative?) and that makes the Earth positive? I'm not sure but I read somewhere in my book (I think) that an electric field has a positive charge so that would mean the Earth has a negative charge.
If anyone could please PLEASE help me with these before it's too late I'd greatly appreciate it. I really need to understand these things better.