Unit 2 -- Car Push Lab Background

Summary

In this engaging physics lab, Mr. Gustin challenges students to determine the mass of his truck using a bathroom scale, tape measures, and stopwatches. He explains the concepts of constant velocity and constant acceleration, emphasizing how net forces relate to friction. Students are tasked with designing two experimental procedures: one to analyze forces at constant velocity, and another to measure acceleration. This hands-on approach not only reinforces theoretical principles but also encourages teamwork and critical thinking, making the learning experience dynamic and interactive.

Takeaways

• 🚗 Mr. Gustin introduces the car push lab, challenging students to find the mass of a truck experimentally.
• 📏 Essential materials include a bathroom scale, tape measures, meter sticks, and stopwatches for the experiment.
• ⚖️ Students are required to create free-body diagrams (FBD) for the truck in two scenarios: constant velocity and constant acceleration.
• ⬆️ At constant velocity, the acceleration is zero, indicating that the net force acting on the truck is balanced.
• 📉 In the constant acceleration model, students must apply greater push forces to overcome friction and achieve acceleration.
• 💡 The frictional force remains constant, allowing students to use it in their calculations for mass determination.
• 🔄 Understanding the relationship between push forces and friction is crucial for modeling the truck's motion.
• 🕒 Students will use stopwatches and distance measurements to determine the truck's acceleration during the experiment.
• 📊 Data collection and analysis are emphasized as key components of the lab procedure.
• 🤔 Mr. Gustin encourages students to ask questions and seek assistance if they face challenges during the lab.

Q & A

What is the main objective of the car push lab?

The main objective is to experimentally determine the mass of a truck using various materials and measurements.

What materials are suggested for measuring the mass of the truck?

Materials include a bathroom scale, tape measures, meter sticks, and stopwatches.

Why is a bathroom scale used in this experiment?

The bathroom scale measures force when compressed, allowing for the conversion of readings into mass and weight.

What two scenarios does Mr. Gustin ask the students to model?

Students are asked to model the truck moving at constant velocity and at constant acceleration.

What does it mean for the truck to move at constant velocity?

Constant velocity means the acceleration is 0 m/s², indicating that the net force acting on the truck is zero.

How does the net force relate to the forces acting on the truck during constant velocity?

During constant velocity, the force of friction is equal to the sum of the pushing forces, resulting in a net force of zero.

What changes when the truck is pushed at constant acceleration?

When pushed at constant acceleration, the net force becomes non-zero, requiring greater push forces to overcome friction.

What tools can be used to measure acceleration in this experiment?

Stopwatches and meter sticks can be used to graphically determine the truck's acceleration.

How can students calculate the mass of the truck?

By measuring the push forces, determining the acceleration, and using the equation F = ma, students can calculate the mass of the truck.

What is the significance of frictional force in the lab?

The frictional force remains constant as it depends on the truck and surface, influencing the push forces needed for both scenarios.