Answer:
<h3><u>
<em>The board should be placed at about an 80-88 degrees angle. </em></u></h3>
<u><em>Explanation:</em></u>
<u><em>This will speed the car up and increase its speed as going down the ramp.</em></u>
Like when you put ice in water it starts going down
The evidence that a chemical reaction occurred is can be change in color , formation of a precipitate , Here in the case when 6 m HCl to the solution of sodium acetylsalicylate, the formation of precipitate that is of aspirin takes places that can be taken as a evidence that a reaction is occured. The reaction can be seen in the image attached.