In Part A of the lab, the echo "duration" is converted to distance $($in $cm).$ If the echo time or duration was $2000$ s$,$ how far away was the reflecting surface? Show you work here.

In Part B of the lab, what digital pin is used to control the green LED?

What is the "name" of the Arduino clock we'll be using? It's mentioned in part C of the lab.

In part $D$ you will be investigating the motion of a small toy dune buggy car. What might you need to tape onto your dune buggy?

You have a plot of an object's position $x$ versus time $t.$ The object moved in one dimension. What quantity gives the velocity? Circle the best answer.

The area

The slope

The $y-$intercept

The $x-$intercept

Consider the following snippet of code. Which LED is turned on$?$ What frequency is heard?

float myValue $=3\mathrm{.}14$;

if $($myValue $>4\mathrm{.}0)$

$\{$

digitalWrite$($redLED$,$ HIGH$)$;

digitalWrite$($greenLED$,$ LOW$)$;

tone$(3,2000)$;

$\}$

else if $($myValue $<mtext\; id="EditorElement\_2539333"></mtext><mn\; id="EditorElement\_2539334">4</mn><mn\; id="EditorElement\_2539335">.</mn><mn\; id="EditorElement\_2539336">0</mn><mi\; id="EditorElement\_2539337">)</mi>$

$\{$

digitalWrite$($redLED$,$ LOW$)$;

digitalWrite$($greenLED$,$ HIGH$)$;

tone $(3,500)$;

$\}$

${?}^1$ I get $34\mathrm{.}3cm.$ Don't forget to divide the duration by $2$ and use speed of sound $34,300c\frac{m}{s}.$