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Physics Classroom is making strides to make our site accessible to everyone. Our site contains 6 navigation areas. The Primary, Secondary, and Page Level navigations have a screen reader version of their nav structure that allows using the left and right keys to navigate sibling navigation items, and up or down keys to navigate parent or child navigation items. The others can be navigated using tabs. The Primary Navigation handles the first 2 levels of site pages. The Secondary (which is not always available) handles the 3rd and 4th level of structure. The Page level navigation allows you to navigate the current page's headings quickly. The Header Navigation contains the Light/Dark Mode toggle, Search, Notifications and account login. The Breadcrumb Navigation contains the breadcrumb of the current page. If the current page has a breadcrumb, you can get to it by skipping to the content and tabbing in reverse (shift plus tab). The Footer Navigation contains links such as Privacy, Contact, about and terms. Some resources contain an Audio Player that can be activated by holding down the T key for 3 seconds, and then using K to pause and resume. While not every area of Physics Classroom is usable purely from keyboard and screen reader, we are committed to continue work on making this possible. If you have questions or need additional help, please use this link to contact us.

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Keeping Track of Momentum - Hit and Stick Collisions - Directions

Using the Keeping Track of Momentum (Hit and Stick Collisions) Concept Builder is quite simple. There are three different difficulty levels, each with the same emphasis but noticeably different question difficulty. For each difficulty level you will be presented with a description of a collision. Information about the momentum of the two colliding objects (Apprentice Difficulty Level) or the mass, speed, and direction of the two colliding objects (Master and Wizard Difficulty Level) is provided. You must analyze the written information and use it to complete a Momentum Table. The Momentum Table displays the momentum of the two colliding objects and of the system of two objects before and after the collision. The change in momentum of the two individual objects and of the system of two objects is also displayed in the table. Entering the momentum values is easy. Simply tap on the cell of the table and use the built-in number pad to enter the values. Once typed in, you can either tap on the Enter button or tap on a different table cell in order to enter another value. Once all the values have been entered, you can tap on the Check Answer button. Your answers will be evaluated and feedback will be given. Red dots will be used to indicate any incorrect values or any values that have not yet been entered. You will be allowed an endless number of opportunities to determine the correct answers; you will not receive the next question until the table is correct and complete. You can use the Help Me! button for assistance.

For each difficulty level, there are two questions which don't involve the completion of a momentum table. These two questions provide a completed momentum table and ask you to make meaning of the table. There are two cells in the table that are highlighted. You must identify which one of the five statements is consistent with the two cells of the table. Tap on the words or on the radio button to the left of the words in order to select your answer option. If you need to deselect the option, then tap a second time. You can tell whether an option is selected because the words will be red and the radio button will be highlighted with a red central dot. Once you are satisfied with your answer, tap on the Check Answer button. Your answer will be evaluated and your Progress Report will be updated.

Your goal is to earn "Stars" and to complete one or more of the difficulty levels. Stars are earned when you demonstrate success with a particular question. Once you show success on all the situations at a particular difficulty level, you will earn the trophy for that level.

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