# Changing velocity of object in space

1. Dec 7, 2016

### Phys_Boi

1. The problem statement, all variables and given/known data

There are two objects in space: a larger (mass = M) and smaller (mass = m). The smaller mass is above the larger object. The smaller object has a velocity (v) that is parallel to the horizontal so that θ = 0. The smaller object is being accelerated by Newtons law of Gravitation. The acceleration vector (a) forms an angle (γ) with the velocity vector (v).

After some time (t), the smaller object has changed its position so that it is to the right of the larger object.

Question:

At time = t, is the velocity is:
a) at angle θ (0° relative to the horizontal)
b) at angle γ - relative to the acceleration
c) none of the above (explain the angle of velocity)

2. Relevant equations
Fg = GM / x2

vf = vi + at

3. The attempt at a solution

2. Dec 7, 2016

### BvU

Make a drawing and post an attempt at solution. PF rules

3. Dec 7, 2016

### epenguin

??

And perhaps your attempt at a solution should start by saying what do you understand by the question, which I find strangely worded, starting with the fact that if there are just two bodies in space there is no 'above ' or 'horizontal'

4. Dec 8, 2016

### TJGilb

Yeah, from what I gather, this problem would best be approached in spherical coordinates with the origin at the center of the larger mass (since it sounds like it's a planet or something similar), though the wording makes no sense as is.