Small suggestion: this should be an `Object` method: ``` obj->Force += obj->Mass * m_gravity; // apply a force obj->Velocity += obj->Force / obj->Mass * dt; o

Small suggestion: this should be an `Object` method: ``` obj->Force += obj->Mass * m_gravity; // apply a force obj->Velocity += obj->Force / obj->Mass * dt; obj->Position += obj->Velocity * dt; obj->Force = vector3(0, 0, 0); // reset net force at the end ``` As in ``` void Object::Step(double dt_s, const vector3& g_mps2) { Force += Mass * g_mps2; // apply a force Velocity += Force / Mass * dt_s; Position += Velocity * dt_s; Force = vector3(0, 0, 0); // reset net force at the end } ```