Skill 6 of 15
In Progress

Equation rearrangement

Previously (in the Throwing & free falling skill) we arrived at these two equations for our flying orange-cannon shot orange:

$\displaystyle s_y=v_{y,0}t- \frac12 gt^2\qquad$ and $\qquad {s_x}=v_{x,0}t$

Its technical sheet tells a muzzle velocity of $5\,\mathrm{m/s}$. At your shooting angle this could mean $4\,\mathrm{m/s}$ vertically and $3\,\mathrm{m/s}$ horizontally. So, we know the values $v_{x,0}=3\,\mathrm{m/s}$ and $v_{y,0}=4\,\mathrm{m/s}$.1 They are not unknowns anymore. In the two equations there are thus only three unknowns left: $s_x$, $s_y$ and $t$.2

Subscribe to valuable engineering skills for your resume or CV

Try full access with a 7-day free trial on all subscriptions.


Already subscribing? Log in:


  1. A History of Mathematical Notations (Dover Books on Mathematics)’ (book), Florian Cajori, Dover Publications, 1st ed., 2011,, ISBN 9780486677668
  2. Essentials of Logic’ (book), Irving Copi, Carl Cohen & Daniel Flage, Taylor & Francis, 2nd ed., 2016,, ISBN 9781315389011