Questions 13-16. The following section focuses on an investigation about collisions.
Read the information below and use it to answer the selected-response questions and constructed-response question that follow. A group of students conducted an investigation to learn about collisions. The students used an air track and two gliders, X and Y. Friction was negligible on the air track. The investigation had the following steps:
- The spring pushed glider X.
- Glider X moved a distance of 0.7 m to the right at a constant velocity.
- Glider X collided with glider Y.
The diagram shows glider X moving toward glider Y after glider X was pushed by the spring. The students recorded the data from three trials of the investigation. A negative velocity indicates that the glider moved to the left, and a positive velocity indicates that the glider moved to the right. The data are shown in the table. No velocity data were recorded for glider Y after the collisions.
 In trial 1, which of the following best explains what happened to the kinetic energy of glider X after it collided with glider Y? |
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 During trial 1, glider X was moving to the right before the collision with glider Y, and then moved to the left after the collision with glider Y.
Part A. Based on the data table, calculate the momentum of glider X before the collision in trial 1. Show your calculations and include units in your answer.
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This question has four parts.
Homemade ice cream can be made using a metal container in a bucket. The metal container is filled with the ice cream ingredients (cream, sugar, and flavoring). The bucket is filled with salty water and ice cubes. The ice cream
ingredients are stirred using a handle. The diagram shows the ice cream maker.
Part A. The parts of the ice cream maker system have different initial temperatures.
• The metal container and the ingredients both have an initial temperature of 10°C.
• The salty water with ice cubes has an initial temperature of –15°C.
The temperature of the air surrounding the bucket is 20°C.
Draw an arrow pointing left or right in each box to show how heat flows through the system. |
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Part B. The ingredients for vanilla ice cream have a specific heat of 3.22 J/g • °C and a freezing point of –5.6°C.
Calculate the amount of thermal energy transfer required to reduce the temperature of 1500 g of vanilla ice cream ingredients from 10°C to –5.6°C. Show your calculations and include units in your answer.
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Part C. The ingredients for chocolate ice cream have a specific heat of 3.11 J/g • °C and a freezing point of –5.6°C.
Identify whether reducing the temperature of 1500 g of chocolate ice cream ingredients from 10°C to –5.6°C will require more, less, or the same amount of thermal energy transfer as is required to reduce 1500 g of vanilla
ice cream ingredients from 10°C to –5.6°C. Explain your reasoning.
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Part D. As the ice cream is being made, the temperature of the salty water with ice cubes is constant.
Explain how there can be thermal energy transfer between the metal container and the salty water without the temperature of the salty water changing.
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