## Trajectory - Angle Launched Projectiles - Directions

### How it Works:

The Trajectory - Angle Launched Projectiles Concept Builder is quite simple to use. There are three activities in all. In each activity, you will do different things. In Activity 1 - Horizontal and Vertical Speed, there will be two types of questions. In one type, you will rank the horizontal speed and the vertical speed of a projectile at three different locations along its trajectory. You will do this by tapping on the cells of a table to rank the horizontal speed (Vx) and the vertical speed (Vy) from greatest to least. Once you tap on a table cell, the contents of the cell change from Smallest to Middle to Greatest. If a speed value is the same for all locations, then tap on the text "Tap here if all the same." located below the table under the Vx and the Vy columns. Once you have ordered the three locations from greatest to smallest (or all the same value), a Check Answer button appears. If satisfied with your answers, then tap the button. In addition to the questions requiring you to rank the three locations, there is a second type of Multiple-Choice style question in which you must describe how the horizontal speed and the vertical speed change over the course of the entire trajectory or a portion of the trajectory. Simply tap on the answer options to complete each of the two statements. Once you have selected two answers, a Check Answer button will appear. If satisfied with your two answers, then tap the button. Once a Check Answer button is tapped, you will receive immediate feedback and your Progress Report will be updated.

In Activity 2 - Vector Diagrams, you will have three questions to answer. You must do the same thing for each question - drag the proper set of horizontal and vertical velocity vectors to three different locations on a vector diagram. You will be given a set of vectors for one location, six possible answer options, and three target locations to which you must drag one vector set each. Simple tap on the answer option, drag to the target location (a flashing dot), and let go of the answer option. Your selected option will then snap into place. If you happen to change your mind, simply drag a different vector set to that location and let go; when you let go, the new vector set will replace the previously chosen set. Once you have dragged answer options to each of the three locations, a Check Answer button will appear.  If satisfied with your answers, then tap the button. You will receive immediate feedback and your Progress Report will be updated.

In Activity 3 - Time, Time, Time, you will have one type of question to answer four different times. In each question, you will be given the appearance of the vector diagram at a given moment in time. You will then have to match three different timers - with times marked 1.0 s, 3.0 s, 4.0 s (or something similar to this) - to three of six provided vectors. You will have to think hard about how the horizontal and vertical speed change with respect to time. You will accomplish this task by tapping on each time, dragging it to one of the six answer options, and letting go of the timer. The timer will snap into place when you do. If you happen to change your mind, simply drag a different timer to that location. Once all three timers have been dragged to one of the six locations, a Check Answer  button will appear.  If satisfied with your answers, then tap the button. You will receive immediate feedback and your Progress Report will be updated.

### Getting Help

You will notice that there is a Help Me button underneath the Progress Report. You should learn to use this feature of the program. It's how you can turn an exercise in answering questions into an exercise in learning. Tapping on the Help Me button will open a page with help that is specific to each task. Of course, the Help pages are only helpful if you read them. So take the time to read them. Each Help page contains four sections: a discussion of the The Basic Idea, a display of the Question you are facing (or a similar question with different numbers), a section titled "How to Think About This Situation", and a set of links to resources in our Tutorial section. You should pay attention to the section titled How to Think About This Situation. You will find what you need to know in the three or four paragraphs of this section. You will also become a better Physics student for doing that. That is, after all, the goal of such an activity as Trajectory - Angle Launched Projectiles​.

Thanks for being patient with the Directions. Happy learning!