When an object, such as a soccer ball or car, moves, the air that the object moves through tries to prevent the motion. The opposing force caused by the air an object moves through is often referred to as air resistance, or drag. A student is designing several experiments to determine what quantities affect how big is the drag force on a moving object. 1. The student hypothesizes that the drag force could be affected by how fast the object is moving (its speed), the object's mass, and the cross-sectional area of the object as it "faces into the wind," as illustrated in the figure. Falling Sphere Falling Brick 25 20 Cross-Section is a Circle 2. From their experiment, a student creates a graph showing how mass affects the drag force on an object. The student also writes a brief statement of what is the be math model (claim) for the data and why (evidence). Question: For the graph, do you agree or disagree with the student's claims and supporting evidence? Why or why not? Graph 3: Drag Force ( 0.2 MathBits Cross-Section is a Rectangle 0.4 Fd = -0.1531m + 20.801 0.6 0.8 mass (kg) 1.2 1.4 1.6 Fig. 3. How mass affects the drag force for different metal cylinders with the same cross-sectional area moving at the same speed. The graph shows a straight line with a small negative slope, which suggests a linear model. The negative slope makes sense because objects with more mass will be less affected by the air, reducing their drag force.

When an object, such as a soccer ball or car, moves, the air that the object moves through tries to prevent the motion. The opposing force caused by the air an object moves through is often referred to as air resistance, or drag. A student is designing several experiments to determine what quantities affect how big is the drag force on a moving object. 1. The student hypothesizes that the drag force could be affected by how fast the object is moving (its speed), the object's mass, and the cross-sectional area of the object as it "faces into the wind," as illustrated in the figure. Falling Sphere Falling Brick 25 20 Cross-Section is a Circle 2. From their experiment, a student creates a graph showing how mass affects the drag force on an object. The student also writes a brief statement of what is the be math model (claim) for the data and why (evidence). Question: For the graph, do you agree or disagree with the student's claims and supporting evidence? Why or why not? Graph 3: Drag Force ( 0.2 MathBits Cross-Section is a Rectangle 0.4 Fd = -0.1531m + 20.801 0.6 0.8 mass (kg) 1.2 1.4 1.6 Fig. 3. How mass affects the drag force for different metal cylinders with the same cross-sectional area moving at the same speed. The graph shows a straight line with a small negative slope, which suggests a linear model. The negative slope makes sense because objects with more mass will be less affected by the air, reducing their drag force.