Amatch burns because of what type(s) of properties?

a. physical only
b. chemical only
c. physical and chemical

Ineed to find the answer of this question because i dont understand it

Which can be observed only in a microscopic view? a) structure of a muscle cell b) shape of a soybean plant c) foam insulation d) x-ray of a knee joint

A2-kg bowling ball is 1 meter off the ground on a post when it falls. just before it reaches the ground,its traveling 4.4 m/s. assuming that there is no air resistant, which statement is true a. the initial potential energy is less then the final kinetic energy b. the mechanical energy is not conserved c. the mechanical energy is conserved d. the initial potential energy is greater than the final kinetic energy