\begin{frame}
  \frametitle{Exercises}
  
  \begin{exampleblock}{}
    Assume that a ball is dropped,
    and we have the following measurements:
    \begin{itemize}
      \item height at time $0s$ is $490$m
      \item height at time $2s$ is $472$m
      \item height at time $4s$ is $414$m
    \end{itemize}
    \pause
    Find a quadratic function for the height of the ball after time $t$.\\
    \pause
    When does the ball hit the ground?
  \end{exampleblock}
  \pause
  
  We look for a function of the form:
  \begin{talign}
    h(t) = at^2 + bt + c
  \end{talign}
  \pause
  We know
  \begin{talign}
    &h(0) = c = 490\\
    &\mpause[1]{h(2) = 2^2a + 2b + 490 = 472}\\
    &\mpause[2]{h(4) = 4^2a + 4b + 490 = 414}
  \end{talign}
\end{frame}