Robo-mentum: Mass, Velocity, and Momentum Relationships
Students assemble vehicles from their STEM kits.Copyright Diomil Haro, 2023
Student groups use STEM vehicle kits to learn about the relationships between linear momentum, mass, and velocity. Each group assembles their vehicle and then runs tests and gathers data to calculate their vehicle’s velocity/speed and linear momentum. This data is then used to create scatter plots of the three variables (linear momentum, mass, and velocity/speed), and the Desmos graphing calculator is used to model a direct relationship using linear regression, as well as model an inverse relationship using exponential regression.
Cars built before 1959 did not have seat belts. The seat belt was meant to keep the driver and passengers solidly attached to the car to prevent injuries in the event of a crash. However, during a crash people are still at risk of hitting the steering wheel or dashboard at high speed. To remedy this, engineers developed the airbag. When the car’s computer senses an extreme deceleration, the airbag deploys, which gradually changes the head’s momentum. A change in momentum over a longer time frame reduces the force on the body and helps prevent head injuries.
Momentum is also applied in mechanical engineering, such as when determining the reaction force on a pipe junction due to either a laminar or turbulent flow of the fluid used in the piping system. Knowing the force applied by the fluid on the junction will help determine what type of material, thickness, connection, etc. should be used to create an effective system.
After this activity, students should be able to:
- Assemble a vehicle using a STEM vehicle kit.
- Define linear momentum, mass, and velocity.
- Generalize the relationships between linear momentum, mass, and velocity.
- Measure an object’s mass (digital weighing scale), distance set to travel (meter stick), and time spent traveling a set distance (phone timer).
- Calculate an object’s velocity/speed and linear momentum (calculator).
- Create a scatter plot based on the three variables (linear momentum, mass, and velocity/speed (Desmos graphing calculator).
- Use the Desmos graphing calculator to model a direct relationship using linear regression, and model an inverse relationship using exponential regression.