Name _______________________________________ Pd ____ Date _________________________ Physics: Momentum Exploration Introduction Mathematically, momentum is defined as the product of an object’s mass and velocity, 𝑝 = 𝑚×𝑣. This is a simple enough quantity to calculate. How can we conceptually describe or explain momentum, on the other hand, may not be so easy. Your goal in the exploration is to have a sound conceptual understanding of momentum. Objectives • How does an object’s velocity and mass affect its stopping distance? • Qualitatively describe momentum. Materials & Equipment • Short Track • Dynamics Cart • Mass Blocks for Dynamic Cart • Spring Scale •
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Digital Balance Large Rubber Band Ruler Books
Procedure Design a set of experiments that allow you to determine how the velocity and mass of an object affects its stopping distance and conceptually (qualitatively) describe momentum. Helpful Hints • You need to measure the stopping distance of the dynamics cart when it is at constant velocity. This is best done by placing the rubber band barricade about 1 ½ cart lengths beyond the end of the ramp. •
To calculate the stopping force you should measure the distance the barricade stretched to stop the forward motion of the cart. After you’ve completed your trials attach a spring scale to the barricade and slowly pull the spring scale until the barricade is stretched the same distance as the cart stretched it. This is your stopping force. •
You’ll want to run two or three trials for each set of variables to make sure your results are reproducible. Data Create a data table on a separate sheet of paper to record your data that you measured in the lab. Data Analysis Create a results table that shows the mass of the cart, the stopping force, angle of incline, theoretical velocity, and theoretical momentum for each trial. Also show your sample calculations on this sheet. •
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To calculate the angle of incline use the formula, 𝜃 = sin!! , where h is the height of the track above the lab !
bench and l is the length of the track. •
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To calculate theoretical velocity use the formula, 𝑣 = 2𝑔 cos 270° − 𝜃 𝑑, where g is the acceleration due to gravity, θ is the angle of incline and d is the distance the cart traveled down the incline. To calculate momentum use the formula, 𝑝 = 𝑚×𝑣, where p is momentum. Conclusions 1. How does an object’s velocity and speed affect its stopping distance? 2. Does one of these quantities have a greater effect on stopping distance or do they both have and equal effect? (In other words, if you doubled the velocity and kept mass constant would it have a different effect or the same effect on stopping distance compared to if you kept the velocity constant and doubled the mass?) 3. Conceptually (qualitatively) explain momentum.