Teacher guide featuring 15 labs designed for Advanced Placement Physics 1.
Students use a motion sensor to determine the relationship between a system’s mass, acceleration, and the net force being applied to the system.
What factors affect the acceleration of an object or system? Experimentally determine the relationship between an object’s or system’s mass, acceleration, and the net force being applied to the object or system.
The Structured version of this activity is divided into two parts. In both parts, students use a dynamics track and cart and set up the system so a mass hangs over a pulley at the end of the level track, accelerating the cart as the mass falls to the floor.
Using a motion sensor mounted at the end of the track opposite the pulley, students measure the cart's velocity as it accelerates, and then use the slope of the velocity versus time graph to determine the cart’s acceleration.
Part 1 – Students keep the amount of hanging mass constant (constant net force) while varying the mass added to the top of the cart (varying system mass), and observe how this affects the acceleration of the system. Student data will show a linear relationship between acceleration and 1/mass.
Part 2 – Students keep the system mass constant but change the net force acting on the system by moving mass from the top of the cart to the mass hanger, and observe how this change affects the acceleration of the system. Student data will show that the acceleration of the cart is proportional to the net force acting on the cart.
Combining these two proportionalities, students experimentally derive the equation that summarizes Newton’s Second Law.
The Ohaus Scout Pro Balance 2000g listed in the Materials and Equipment section is for classroom use, not individual lab stations.
This experiment may require software and an interface for data collection.