Name: Physics Lab Collisions Lab: Don’t Lose Momentum! A Conservation of Momentum Lab Purpose: To investigate the application of the Law of Conservation of Momentum in collisions. Procedure: 1. Open up the simulation: Collision Lab Simulation 2. Choose Explore 1-D. Click on “More Data” to expand the data table. Part 1: Scenario #1: 100% Elastic collision between balls of equal mass 1. Make a hypothesis about initial and final momentums before playing the sim. 2. Complete the following data tables for each ball before and after each trial. “Before” represents position “x” and “after” represents the time when position “x” has switched for the two balls. Use the rewind tool to adjust the sim to that moment to fill in the data table. 3. Perform 2 trials with 2 different sets of balls of equal masses. Part 2: Scenario #2: 100% Elastic collision between balls of unequal mass 1. Make a hypothesis about initial and final momentums before playing with the sim. 2. Complete the following data tables for each ball before and after each trial. “Before” represents position “x” and “after” represents the time when position “x” has switched for the two balls. Use the rewind tool to adjust the sim to that moment to fill in the data table. 3. Perform 2 trials with 2 different sets of balls of unequal masses. Part 1 Data Tables Trial 1 Before Sim Ball Mass (kg) Velocity (m/s) Momentum (kg*m/s) Mass (kg) Velocity (m/s) Momentum (kg*m/s) Mass (kg) Velocity (m/s) Momentum (kg*m/s) Mass (kg) Velocity (m/s) Momentum (kg*m/s) 1 2 Total Trial 1 After Sim Ball 1 2 Total Trial 2 Before Sim Ball 1 2 Total Trial 2 After Sim Ball 1 2 Total Part 2 Data Tables: Trial 1 Before Sim Ball Mass (kg) Velocity (m/s) Momentum (kg*m/s) Mass (kg) Velocity (m/s) Momentum (kg*m/s) Mass (kg) Velocity (m/s) Momentum (kg*m/s) Mass (kg) Velocity (m/s) Momentum (kg*m/s) 1 2 Total Trial 1 After Sim Ball 1 2 Total Trial 2 Before Sim Ball 1 2 Total Trial 2 After Sim Ball 1 2 Total Part 3 1. Create 3 more distinct scenarios, all using the 1-D Collisions simulation ○ one scenario should address a totally inelastic collision (0% elasticity). ○ For your other 2 scenarios, consider which variables you’d like to investigate 2. For each scenario: list the elasticity percentage, fill out the data tables, and make a hypothesis whether or not each will follow conservation of momentum. 3. Collect some data to investigate your hypothesis. Scenario #3 Elasticity %: Hypothesis: Before Sim Ball Mass (kg) Velocity (m/s) Momentum (kg*m/s) Mass (kg) Velocity (m/s) Momentum (kg*m/s) Mass (kg) Velocity (m/s) Momentum (kg*m/s) Mass (kg) Velocity (m/s) Momentum (kg*m/s) 1 2 Total After Sim Ball 1 2 Total Scenario #4 Elasticity %: Hypothesis: Before Sim Ball 1 2 Total After Sim Ball 1 2 Total Scenario #5 Set the elasticity to a percentage of your choice Elasticity %: Hypothesis: Before Sim Ball Mass (kg) Velocity (m/s) Momentum (kg*m/s) Mass (kg) Velocity (m/s) Momentum (kg*m/s) 1 2 Total After Sim Ball 1 2 Total Analysis Questions: 1. What is the relationship between the initial and final total momentums in Scenario 1? In Scenario 2? 2. Describe the motion of the balls before and after the collision in Scenario 1. 3. Describe the motion of the balls before and after the collision in Scenario 2. 4. Summary Statement: In a minimum of 3 sentences, describe the main ideas learned in this activity regarding initial and final total momentum in these collisions. How does an increase in mass affect an object’s velocity? Sample Problems: 1. A lab cart with a mass of 4 kilograms moving at 2 meters per second collides with and sticks to an identical lab cart initially at rest. What is the final speed of the lab carts after the collision? [Neglect Friction]. 2. A car with a mass of 1500 kg moving at a speed of 45 m/s collides with and sticks to a parked car with a mass of 1000 kg. a. Determine the total momentum of the two-car system before the collision. b. Determine the total momentum of the two-car system after the collision. [Neglect Friction]. 3. A 1-kg cart (CART A) moving with an unknown speed on a horizontal surface collides with a second 1-kg cart (CART B) initially at rest. If the carts lock together and move at a speed of 0.25 m/s, determine the initial speed of cart A. [Neglect Friction]. 4. A 1500 kg car moving at 20 m/s collides with a 2300 kg car that is waiting at rests at a traffic light. After the collision, the cars lock together and slide. Eventually, the combined cars are brought to rest by a force of kinetic friction as the rubber tires slide across the dry, level asphalt road. a. Calculate the speed of the locked-together cars immediately after the collision. b. Calculate the magnitude of the frictional force that brings the locked-together cars to rest.
