Investigación de Aula en una Clase Magistral de Física -

Calor – Ondas

Tomas Rada Crespo Ph.D. Profesor del Dpto de Física

Universidad del Norte trada@uninorte.edu.co

A. < 20 estudiantes

B. 20 – 50 estudiantes

C. 50 – 100 estudiantes

D. 100 – 150 estudiantes

E. > 150 estudiantes

¿Qué tan grande son sus cursos?

¿Cuál campo del saber representan los participantes?

A. Ciencias

B. Matemáticas

C. Artes

D. Lenguas extranjeras

E. Otros

Un poco de historia

• En 2011 comenzó la clase magistral en Física Calor Ondas.

• Este cursó pasó de un curso regular de 24 a grupos de 80-120 estudiantes

• Los primeros dos semestres fueron realizados en la forma tradicional.

• El porcentaje de estudiantes que retiraban antes o perdían la asignatura se incrementó considerablemente.

Antecedentes

• De acuerdo a la opinión de los estudiantes:

Sienten que es difícil participar en cursos grandes,

Sus profesores no los conocen en esos cursos.

El ambiente en la clase en estos cursos no son buenos para su concentración.

…

Aprovechando una oportunidad!

Gracias a una iniciativa lanzada en uninorte en 2012 para promover cambios en la estrategia de enseñanza,

• el proyecto comenzó :

1. para promover aprendizaje significativo activo en los estudiantes,

2. para mejorar los resultados globales en los estudiantes.

¿Qué hacer?

• El curso e convirtió en un reto pedagogico

• Acciones: 1. Sacudir el rol pasivo de los estudiantes Se

introdujeron clickers

2. trabajar en el compromiso de los estudiantes Lecturas previas y experimentos demostrativos

3. Encontrar respuestas acerca de como los estudiantes aprenden algunos temas claves en los relacionados con los programas de ingeniería Comenzó SoTL.

• Pregunta problema :

• ¿Qué grupo, de una clase magistral, obtiene mejores resultados al determinar el ángulo de fase de un mov armónico simple, a través de la aproximación matemática o gráfica?

Conexión

Teoría Experimento

Mundo Real

Vibrations Oscillations

HSM is a component of wave

Movimiento Armonico Simple MAS

Simple Harmonic Motion (SHM)

x(t) = A cos( t + )

Amplitude Angular

frequency Phase angle Displacement

Velocity, v, Acceleration, a, vmax, amax,

frecuency, f, Period, T, mass, m, Elastic constant,

k, Force, F,

Kinetic Energy, Ek, Potential Energy, Ep ,,

Model

mass

k

Model

mass

k

Simple Harmonic Motion (SHM)

~

A ~

Imagine a block of mass20 kg attached to a end of a spring that oscillates with SHM along the x axis. Initially, (t=0), it is located at -4 cm away from the origin x=0, it has a speed of -15 cm/s and an acceleration of 100 cm/s2.

Simple Harmonic Motion (SHM) Graph vs. Equation

~

A ~

Graphical Approach

Imagine a block of mass 20 kg attached to a end of a spring that oscillates with SHM along the x axis. Initially, (t=0), it is located

at -4 cm away from the origin x=0, it has a speed of -15 cm/s and an acceleration of

100 cm/s2.

Mathematical Approach

Questions: a) Determine the angular frequency. b) Determine the Phase angle.

Additionally: c) Write the HSM equation )cos()( tAtx

Some mathematical relations are needed

Results Graph vs. Equation

~

A ~

Imagine a block of mass 20 kg attached to a end of a spring that oscillates with SHM along the x axis. Initially, (t=0), it is located

at -4 cm away from the origin x=0, it has a speed of -15 cm/s and an acceleration of

100 cm/s2.

Graphical Approach Mathematical Approach

76% 71% 70%

33%

0%

20%

40%

60%

80%

100%

Attempt Right Attempt Right

Graphical Approach

Graph

83%

60%

84%

44%

0%

20%

40%

60%

80%

100%

Attempt Right Attempt Right

Mathematical Approach

A

Math

Results

83%

60%

84%

44%

76%

71% 70%

33%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

Attempt Right Attempt Right

Summary

A /

Math

Graph

202 207

GRACIAS!!!!

Open-ended questions

Q1. What variables can the student identify? (to name)

Q2. What other variables can the student relate to the

problem? (to find)

Q3. How does the student calculate other variables? (to

evaluate)

Imagine a block of mass 20 kg attached to a end of a spring that oscillates with SHM along the x axis. Initially, (t=0), it is located

at -4 cm away from the origin x=0, it has a speed of -15 cm/s and an acceleration of

100 cm/s2.

Imagine a graphic (with values) that represent the displacement -of a known mass attached to a spring- vs

time. In term of variables and

constants :

Results

Imagine a block of mass 20 kg attached to a end of a spring that oscillates with SHM along the x axis. Initially, (t=0), it is located

at -4 cm away from the origin x=0, it has a speed of -15 cm/s and an acceleration of

100 cm/s2.

64%

4% 4%

56%

0%

10%

20%

30%

40%

50%

60%

70%

Answered 1 Varible 2 variables 3 and 4

Question 1

70%

26% 20% 25%

0%

10%

20%

30%

40%

50%

60%

70%

80%

Answered 1 Varible 2 variables 3 or more

Question 2

% de Estudiantes

58%

22% 19% 17% 0%

10%

20%

30%

40%

50%

60%

70%

Answered 1 Varible 2 variables 3 or more

Question 3

% de Estudiantes

Results

Imagine a graphic (with values) that represent the displacement -of a known mass attached to a spring- vs

time. In term of variables and

constants :

85%

13%

53%

18%

0%

20%

40%

60%

80%

100%

Answered 1 Varible 2 variables 3 and 4

Question 1

86%

32% 17%

36%

0%

20%

40%

60%

80%

100%

Answered 1 Varible 2 variables 3 or more

Question 2

% de estudiantes

78%

37% 13%

27% 0%

20%

40%

60%

80%

100%

Answered 1 Varible 2 variables 3 or more

Question 3

% de estudiantes

Knowledge requirements

• Open questions

Q1. What variables can the student

identify? (to name)

Q2. What other variables can the student

relate to the problem? (to find)

Q3. How does the student calculate other

variables? (to evaluate)

According to Bloom Taxonomy

Knowledge

Application

Evaluation

Conclusions

• The percentage of students who try to find the A/ variables is close ~ 80±3% but 71% graph

60% math

• The percentage of students who try to find the is ~ 80% (44% ) from math approach and 70% (33% ) from the graphical approach

Quantitative

Conclusions

• Stundents tends to have lower response rate when they face the mathematical approach (M.A.) than when they face a graphical one(G.A.).

• In the M. A. 88% of students identified 3 or 4 variables, compared to 18% from the G. A.

• In relation to other variables only 45% got 2 or more from M. A. (53% from G. A.)

• The third question is 36% from M.A. vs. 40 % G. A.

Open questions