True or false your vocal cords act like a guitar string when it comes to sound

In a given chemical reaction, the energy of the products is greater than the energy of the reactants. which statement is true for this reaction?

Suppose you plot the distance traveled by an object at various times and you discover that the graph is not a straight line. what does this indicate about the object's acceleration?

The illuminance of a surface varies inversely with the square of its distance from the light source. if the illuminance of a surface is 120 lumens per square meter when its distance from a certain light source is 6 meters, by how many meters should the distance of the surface from the source be increased to reduce its illuminance to 30 lumens per square meter?