Melting, boiling, anf bending are physical changes but why is burning a chemical change

If y gets smaller as x gets bigger and y have an relationship?

You charge a parallel-plate capacitor, remove it from the battery, and prevent the wires connected to the plates from touching each other. when you increase the plate separation, what happens to the following quantities?

On mars a rock falls an unknown vertical distance from a resting position and lands in a crater. if it takes the rock 2.5 seconds to fall, how high is the cliff the rock fell from? mars' surface gravity is 3.8 m/s2. a. 9.5 m b. 11.9 m c. 15.2 m d. 23.8 m