RoboCat: Mousetrap Car

#### State Standards

• 1. Newton’s laws predict the motion of most objects. As a basis for understanding this concept:
• 1.a. Students know how to solve problems that involve constant speed and average speed.
• 1.b. Students know that when forces are balanced, no acceleration occurs; thus an object continues to move at a constant speed or stays at rest (Newton’s first law).
• 1.d. Students know that when one object exerts a force on a second object, the second object always exerts a force of equal magnitude and in the opposite direction (Newton’s third law).
• 2. The laws of conservation of energy and momentum provide a way to predict and describe the movement of objects. As a basis for understanding this concept:

#### Project Summary

The mousetrap laboratory was a two part project, one part as a class, one part in groups. The first portion was a data-collecting session where larger groups worked together to collect information and calculate the acceleration and final velocity of the “control” mousetrap cars. Afterwards, students collected a new set of data based on a single modification to the variables of the mousetrap vehicle. The second portion was a hands-on building experience where students used the information collected and calculated from the modified mousetrap cars to create a mousetrap vehicle of their own with optimum acceleration and final velocity. Data from the student-constructed mousetrap vehicle was used to create a report detailing the effects and effectiveness of the modifications the student made.

#### How I Learned

This project required skills involving the formulas of acceleration, displacement, and velocity. It also required practical skills to help construct the mousetrap vehicle with good craftsmanship. The four primary equations that we learned in class for velocity and acceleration were essential in this project. They were used to find the initial velocity, final velocity, and acceleration the vehicle achieved. This project relates to real life situations where car manufacturers might want to test the power of a new model, or for racers to find out how well their vehicle performed. It also has more mundane applications such as finding out how fast one is travelling on a toboggan downhill.

#### What I Learned

From this project I learned that a single chassis mousetrap requires far more precision than a two-part chassis. The single-spine chassis allows a high degree of freedom for the axles to articulate, creating unnecessary stresses and frictions which cause the vehicle to swerve and turn. Data from the class lab gave me the information that maximum power from a mousetrap is exerted at 150 degrees from a fully closed position. Inference and testing told me that a lighter vehicle would reach a higher velocity with higher acceleration.