Question

What does proportion means exactly
What is ....is directly proportional .... In physics

Answer 1

In Physics and other branches of Science or Subjects it is applied and used to describe variables. If change in one variable is always accompanied by a change in another variable, and if the changes between the two are always relaxted by a constant multiplier, two variables are termed as proportional to each other.


Proportional means that something changes with respect to something else. For instance, ants eat food, and the more food they eat the more they can reproduce. Thus, the population growth of the ants is proportional to the amount of food. You could also say that the population growth is "inversely proportional" to the amount of ant killer in their environment. This is usually facilitated by use of a constant of proportionality, sometimes called k. When something is proportional to something else, it does not mean the values are equal, just that they change with respect to eachother. The constant of proportionality serves as a multiplier. If T is the population growth of ants, and P is the amount of food in their environment. You could say that: T ∝ P T ∝ P More specifically, that means that the values likely only differ by a constant, so you can say: T = k P T = k P An example of inversely proportional would be something like: T = k 1 M T = k 1 M where M is ant killer, poison, or whatever I said before.

DIRECTLY PROPORTION

• Two quantities are said to be in direct proportion (or directly proportional), if one is a constant multiple of the other, i.e. y is said to be directly proportional to x if y = kx where k is a constant.