title: Simple bouncing calculations going wrong
body: <p>im trying to learn python so that i can play around with mathematics. Ive been trying to implement a very simple simulation of a bouncing object with minimal physics but it does not seem to be working properly. The calculations should give me a wave pattern but for some reason the numbers keep decreasing. Is this some sort of math artifact that happens in Python? There is no reason for the numbers to be decreasing from my understanding since im only using very trivial arithmetics.</p>
  
  <pre><code>import sys, pygame
  
  velocity = 0
  acceleration = 0.1
  ycord = 50
  
  while 1:
  
      pygame.time.Clock().tick(10)
  
      velocity -= acceleration
      ycord += velocity
  
      if ycord &lt;= 0:
      velocity *= -1
  
      print (ycord)
  </code></pre>