From 20c1722e4bf5284ffd5fd8975ae094fc57328546 Mon Sep 17 00:00:00 2001
From: Andrea Lin <andrealin2018@gmail.com>
Date: Thu, 10 Aug 2017 10:03:35 -0600
Subject: [PATCH] Change initial speed on Intro screen, see #88

---
 js/common/model/ProjectileMotionModel.js | 5 +++--
 js/intro/model/IntroModel.js             | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/js/common/model/ProjectileMotionModel.js b/js/common/model/ProjectileMotionModel.js
index a4acca76..44b53742 100644
--- a/js/common/model/ProjectileMotionModel.js
+++ b/js/common/model/ProjectileMotionModel.js
@@ -34,9 +34,10 @@ define( function( require ) {
    * @param {boolean} defaultAirResistance -  default air resistance on value
    * @param {number} defaultCannonHeight - optional, defaults to 0, only used by Intro screen
    * @param {number} defaultCannonAngle - option, defaults to 80, only used by Intro screen
+   * @param {number} defaultInitialSpeed - option, defaults to 80, only used by Intro screen
    * @constructor
    */
-  function ProjectileMotionModel( defaultProjectileObjectType, defaultAirResistance, defaultCannonHeight, defaultCannonAngle ) {
+  function ProjectileMotionModel( defaultProjectileObjectType, defaultAirResistance, defaultCannonHeight, defaultCannonAngle, defaultInitialSpeed ) {
 
 
     // @public {ObservableArray.<Trajectory>} observable array of trajectories, limited to 5
@@ -60,7 +61,7 @@ define( function( require ) {
     this.cannonAngleProperty = new NumberProperty( defaultCannonHeight ? defaultCannonAngle : 80 );
 
     // @public {Property.<number>} launch speed, in meters per second
-    this.launchVelocityProperty = new NumberProperty( 18 );
+    this.launchVelocityProperty = new NumberProperty( defaultCannonHeight ? defaultInitialSpeed : 18 );
 
     // --parameters for next projectile fired
 
diff --git a/js/intro/model/IntroModel.js b/js/intro/model/IntroModel.js
index 7de46dcc..feed04e2 100644
--- a/js/intro/model/IntroModel.js
+++ b/js/intro/model/IntroModel.js
@@ -32,7 +32,7 @@ define( function( require ) {
       ProjectileObjectType.CAR
     ];
 
-    ProjectileMotionModel.call( this, this.objectTypes[ 0 ], false, 10, 0 );
+    ProjectileMotionModel.call( this, this.objectTypes[ 0 ], false, 10, 0, 15 );
   }
 
   projectileMotion.register( 'IntroModel', IntroModel );