Independence of horizontal/vertical motion
http://www.stmary.ws/HighSchool/Physics/home/animations3/Motion/HorizProjVx5.htm
Independence of horizontal/vertical motion
http://www.stmary.ws/HighSchool/Physics/home/animations3/Motion/HorizProjVx5.htm
Independence of horizontal/vertical motion
http://www.stmary.ws/HighSchool/Physics/home/animations3/horizProjectileDropped5.htm
Components of velocity
http://www.stmary.ws/HighSchool/Physics/home/animations3/Motion/VixViyComponents5.htm
add vectors and see resultant
https://phet.colorado.edu/sims/html/vector-addition/latest/vector-addition_en.html
Force and motion, projectiles
http://www.thephysicsaviary.com/Physics/Programs/Labs/ForceDirectionRelativeToMotionLab/index.html
Add together different vectors
http://www.physicsclassroom.com/Physics-Interactives/Vectors-and-Projectiles/Name-That-Vector
Independence of horizontal/vertical motion
http://www.stmary.ws/HighSchool/Physics/home/animations3/projectile5.htm
Find resultant forces in 1D
http://www.thephysicsaviary.com/Physics/Programs/Games/NetForceSimpleGame/index.html
Helen rates this resource as good