Inverse Square Law Forces

Question 1

What is an inverse square law force

Answer 1

An inverse square law force is:
Given bodies at X1,X2, force acting on body X2 towards X1 is a force of the form
F = K(X1 - X2)/(X1-X2)^3 where K is a constant

Question 2

What does inverse square force become if r = norm(X1-X2)

Answer 2

If r = norm(X1-X2), then
Inverse square force becomes
Mod(F) = mod(K)/r^2 hence name

Question 3

What is acceleration of an object close to Earths surface

Answer 3

Acceleration of an object close to Earths surface is:
MX.. = F = -GMmx/r^3 where r = norm(x)
Where m is mass of object, M is mass of earth, G is gravity
So mod(x..) = GM/r^2

Question 4

What is definition of weight

Answer 4

Definition of weight is:

Force F = mg

Question 5

What is equation of motion of a particle near earths surface

Answer 5

Equation of motion of a particle near earths surface is:
X.. = g so integrate twice to find
X(t) = X0 + V0t + 0.5gt^2