関連ワード:  what is vector in physics class 11    what is vector in physics class 11 pdf    what is unit vector in physics class 11    what is position vector in physics class 11    what is null vector in physics class 11    what is displacement vector in physics class 11    what is zero vector in physics class 11    what is equal vector in physics class 11    what is negative vector in physics class 11    what is collinear vector in physics class 11