Mass, Speed, and Momentum: Using Guided Inquiry in the Classroom

The type of inquiry used in the classroom is determined by the amount of information the teacher provides to the students. In using a guided inquiry format, the teacher simply provides the students with a research question, and it is up to the students to determine the method of testing and drawing conclusions from the results of the data collected (Banchi and Bell, 2008). For example, I had the opportunity to conduct a guided inquiry investigation being provided on the the question "How does the steepness of a slope and mass affect a collision outcome?"

I realized I needed to set up a model to demonstrate a scenario in which an object on variable slopes could collide with another object at the bottom of the slope. I decided to use a small toy truck (8 grams), a 27 cc wooden block (5 grams), a cardboard ramp (27.5 cm), three books, a meter stick, and a calculator. I also wanted to determine if the amount of mass could influence the collision outcome so I used a large bolt (12 grams) that could be added to the toy truck. I set up the model with one end of the ramp resting on a book, then simulate the collision by releasing the toy truck from the top of ramp and impacting the wood block on the floor at the base of the ramp. I then measured the distance the block traveled after the collision with the truck five times and calculated the average. I repeated this with ramp at a height of 3 cm, 6 cm, and 9 cm. I then duplicated that process with the 12 g mass attached to the truck and recorded the data from those trials to determine if the amount of mass made a difference in the distance.

Once I determined how I was going to test the research question, I needed to form a hypothesis. My hypothesis is that as the ramp height increases, the distance the block is moved will also increase. Secondly, the added mass will also increase the distance when compared with the data from the toy truck alone. The increase in distance will be a result of the increased speed the truck is able to generate as the ramp height increases thereby impacting the block with a greater force. Subsequently the added mass will provide the truck with more momentum thereby increasing the distance of the block after impact.

The results of the investigation confirm my hypothesis as the data shows that the average distance of the block increased from 16.4cm to 31.8cm as the ramp height increased from 3cm to 9cm for the toy truck alone with a mass of 8g. Similar results were achieved when an additional 12g of mass were added as the distance of the block increased from 26.4cm to 46.6cm when the ramp height increased from 3cm to 9cm. When displayed in a graph, the disparity between the averages in distance at each ramp height comparing truck only and added mass becomes more evident in this visual representation. This leads me to conclude that increasing the height of the ramp and added mass increases the speed of the truck thereby increasing the amount of force at impact due to the added momentum. Since momentum is directly affected by the mass and speed of an object, the evidence from the investigation confirms that claim (Tillery, Enger, and Ross, 2008, p 43).

In conducting this guided inquiry investigation I had to be very careful about setting up my testing model appropriately in order to achieve quantifiable results that would either confirm or reject my hypothesis. In keeping with the engineering design process model I realized the need, brainstormed different design options, selected a design, planned the investigation, created the model, then made necessary improvements along the way (TEACH, 2010). This type of inquiry allows freedom of creativity in constructing a testing model according to my own ideas, and not necessarily the ideas or guidelines imposed by someone else. I actually use this very same investigation in my classroom when studying Newton’s second law of motion as a structured inquiry lesson. The investigation I conducted above is divided into two separate investigations with the first altering the height of the ramp to impact an object, and the second using a fixed ramp height with additional mass added to the vehicle. In both instances, the students are able to determine that the force of the vehicle (momentum) increases as the speed and mass are increased. The students really enjoy both of these investigations as the real world implications are limitless. Relating this to any object that is moving will apply and further reinforce the concept of mass and speed determining the momentum of an object.

I like the concept of using this as a guided inquiry lesson, however many of my students come to fifth grade lacking fluency in the scientific processes necessary to carry out an investigation such as this. For this reason I use structured inquiry in conducting a complex investigation like this one due to the fact there are numerous variables which could affect the outcome thereby rendering the data collected insignificant for achieving the level of understanding of the content. With a significant amount of guidance and intervention as they develop their tests, however, the students should be able to successfully work through the investigation to achieve the desired results.

Guided inquiry allows the students freedom of creativity in designing and carrying out an investigation to find answers to a question provided by the teacher. The teacher’s role during the process is one of support, intervention, and frequent questioning in order to ensure scientific integrity in extending the students thinking and application of the scientific process. It is important to keep in mind however, that the experiment is a product of the students’ knowledge, and too much intervention would then become a product of the teacher. Students need to experience science to truly understand science, and balancing creativity with guidance through the guided inquiry process allows them to do just that.

References:

Banchi, H., & Bell, R. (2008). The many levels of inquiry. Science & Children, 46(2), 26–29.

TEACH Engineering: The Engineering Design Process: Retrieved May 16, 2010 from http://www.teachengineering.org/engrdesignprocess.php

Tillery, B., Enger, E., & Ross. F. (2008). Integrated science (4th ed.). New York: McGraw-Hill.