Learning physics like playing with LEGO


Physics is a science that allows describing situations and evolutions of systems in the real world. It is based on variables that can be measured and equations that relate them and allow their calculation and therefore forecast.

Each variable is like a LEGO piece that is assembled forming equations that correspond to a functional element. The different equations permutate to form a model that is analogous to a LEGO toy that can be used in various ways.

The forms of use correspond to the possible calculations that can be carried out with different constellations of given data and necessary intermediate calculations.

The forms of use correspond to what we call problem solving in physics.


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The Analogy



We can establish an analogy between a real situation and a LEGO toy.

The analogy between reality in the form of a journey and a LEGO toy

The real situation is described by variables and equations that associate them.

The LEGO toy through its bricks and parts that are assembled to form the model.

Each brick thus corresponds to a variable that links different parts as equations do.

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The Variables



If the modeling of a traveling vehicle is considered, the initial position $s_0$ and the final reached position $s$ must be entered:

The analogy between variables and LEGO bricks

Within the analogy, a LEGO brick is associated with each variable. As they are different variables, they are differentiated in this case by their color.

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The Equations



Within the model it makes sense to calculate the path traveled $\Delta s$.

To do this, a new LEGO brick must be introduced into the analogy.

The analogy between equations and LEGO sets

For its calculation, the corresponding equation must be defined, which in this case corresponds to

$\Delta s = s - s_0$

In our analogy, LEGO bricks are connected to form the first unit of our model.

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The Time



To describe the motion in our model it is necessary to introduce time.

In analogy to the position, an initial time $t_0$, the final time $t$ and the elapsed time $\Delta t$ must be entered.

Each of the variables corresponds to a LEGO brick that is represented in the image:

The introduction of time and the analogy with LEGO

Additionally, the elapsed time must be entered, which is an equation of the form

$\Delta t = t - t_0$

This in turn is represented in the analogy a new unit of the LEGO model.

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The Speed



To predict how the vehicle will move, you must enter the speed.

This is defined as the ratio of the distance covered and the time elapsed.

Within the analogy, the bricks of the path traveled are taken with that of the time elapsed and they are mounted on a new brick that represents the speed:

The analogy for the introduction of speed

Thus, the third equation is introduced

$v = \displaystylefrac{\Delta s}{\Delta t}$

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All Equations



If you finish assembling the LEGO model, you get additional relationships that correspond to other descriptions of groups of bricks.

In this way, the model is represented by the five variables already defined and by a total of four equations:

Set of all equations

The central part shows the additional equation that arises from assembling the complete model.

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The Model



Finally, we have the complete model, that is, the variables and the equations that associate them.

Within the analogy there is practically a type of instruction of a LEGO model in which the necessary bricks and the elements that are being built are listed.

Instructions of the model in the LEGO style

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