# SUVAT Simulation - Projectiles

## Instructions

### Getting Started

To launch the ball: use one of the three methods available by selecting its tab in the green section at the bottom. For click and drag, just do what it says on the tin! For the other two methods, set your desired initial values using the sliders, then click the green arrow button to launch.

Most of the instructions you need for this applet are included on screen. Drag the grey block vertically to change the platform height and hit pause if you want to explore the problem for yourself before the animation completes. The animation will end when the ball reaches the ground.

### Meaning of the letters

In this common structure for solving projectile questions, we have 5 letters which you should know the definitions of. These are defined for both the vertical direction, and the horizontal direction. \begin{align} S & \text{: Displacement from Origin} \\U & \text{: Initial Velocity} \\V & \text{: Current Velocity} \\A & \text{: Acceleration} \\T & \text{: Time} \end{align} It's worth noting that time is the same for both vertical and horizontal. In the above simulation, $$A$$ is governed by the gravity slider for vertical acceleration, and is $$0$$ for the horizontal acceleration as we are neglecting air resistance.

### Pausing

It will be easier to pause the animation where you want if you choose a slow animation speed.

You might want to pause to observe values at interesting points during flight, like the turning point or when the ball drops below the original height if it started on a high platform. You can look at the inital U and A values and do your own calculations;
- How long will the ball be in the air for?
- How far will the ball travel by the time it reaches the ground?
- What's the highest point the ball will reach?
- What will be the speed of the ball when it reaches the ground?

### Replaying

You can replay the last launch by clicking the replay button. This will set the gravity and tower height back to the settings they were on, and the ball will follow the exact same same trajectory. You can change animation speed however, and view the same path created in slow motion - which could be helpful for picking out key points.

### Sliders

The gravity and animation speed sliders work and do just as you would expect! One thing to note is that you cannot change the sliders during an animation.

### Ghost trajectory

The trajectory for the previous flight, and the launch vector used, will be shown in white when you click to launch a new ball.

### Oops! I accidentally aimed for the moon...

If you release the ball with your mouse a huge distance away (outside of the apllication display) on a really slow animation speed then it could take an age for the ball to land. There's a failsafe for this very situation. The animation will end itself and display final values if it's been running for over a minute. By this time you probably already got bored and refreshed the page to start over anyway!

### Glitches and Improvements

If you find any glitches or have ideas for how this applet could be improved, please let me know by contacting me on Twitter: @NextLevelMaths.