What is the difference between linearly, directly and inversely proportional relationships?
A relationship is a way of describing how one variable can affect another. If a relationship is linear, then a change in one variable will cause a change in another variable by a fixed amount. An example of this in physics is Force against the Extension of a spring (up until the limit of proportionality!). A directly proportional relationship is a special type of linear relationship. When one variable is equal to 0, the second variable will also have a value of 0. On a graph, there would be a straight line through going the "origin". An inversely proportional relationship is one where an increase in one variable will lead to a decrease in another but how quickly this occurs may vary. An example of this would be Gravitational field strength and distance from the centre of a planet. As the distance increases, the strength of gravity decreases.
Related Physics A Level answers
All answers ▸(ii) Describe and explain how the horizontal component of the water jet varies from point X to point Y. (2 marks)
State assumptions made about the motion of the molecules in a gas in the derivation of the kinetic theory of gases equation.
A block of mass (m) is placed on a rough slope inclined at an angle (a) to the horizontal, find an expression in terms of (a) for the smallest coefficient of friction (x), such that the block does not fall down the slope.
If a ball is thrown on the Moon, the projectile would have a greater range than if it were to have been thrown on Earth. Why is this the case?