Projectile not working ?

#import "Projectile.h"

@implementation Projectile




+(instancetype)projectileAtPostion:(CGPoint)position {

    Projectile *projectile = [Projectile spriteNodeWithImageNamed:@"projectile_1"];
    projectile.position = position;
    return projectile;






}

-(void) moveTowardsPosition:(CGPoint)position {

    //GUIDLINES
    // slope = (Y2 - Y1) / (X2 - X1)
    // Y2 - Y1 = slope (X2 - X1)
    // Y2 = slope * X2 - slope * X3 + Y3

    float slope = (position.y - self.position.y) / (position.x - self.position.x);

    float offscreenX;

    if (position.x <= self.position.x) {
        offscreenX = -10;
    }
    else {
        offscreenX = self.parent.frame.size.width + 10;
        //spfsw
    }




    float offscreenY = slope * position.x - slope * self.position.x + self.position.y;


    CGPoint offScreenPosition = CGPointMake(offscreenX, offscreenY);



    //DISTANCE
    //A + B = c
    float distanceA = offScreenPosition.y - self.position.y;
    float distanceB = offScreenPosition.x - self.position.x;
    float distanceC = sqrtf(powf(distanceA, 2) + powf(distanceB, 2));


    //SPEED
    //distance = speed * time

    //time = distance / speed
    float time =  distanceC / 400;

    SKAction *moveProjectile = [SKAction moveTo:offScreenPosition duration:time];
    [self runAction:moveProjectile];





}


@end

#import "GamePlayScene.h"
#import "Machine.h"
#import "SpaceCat.h"
#import "Projectile.h"
@implementation GamePlayScene

-(void)didMoveToView:(SKView *)view {

    SKSpriteNode *background = [SKSpriteNode spriteNodeWithImageNamed:@"background_1"];
    background.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame));
    [self addChild:background];



    Machine *machine = [Machine machineAtPosition:CGPointMake(CGRectGetMidX(self.frame), 13)];
    [self addChild:machine];


    SpaceCat *spaceCat = [SpaceCat spaceCatAtPosition:CGPointMake(CGRectGetMidX(self.frame), machine.position.y-3)];
    [self addChild:spaceCat];


}



-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    for (UITouch *touch in touches) {
        CGPoint location = [touch locationInNode:self];
        [self shootProjectileTowardsPosition:location];

    }


    SpaceCat *spaceCat = (SpaceCat*)[self childNodeWithName:@"SpaceCat"];
    [spaceCat runAction];


}


-(void) shootProjectileTowardsPosition:(CGPoint)position {

    Machine *machine = (Machine*) [self childNodeWithName:@"Machine"];



    Projectile *projectile = [Projectile projectileAtPostion:CGPointMake(machine.position.x, machine.position.y+machine.frame.size.width+7)];


    [self  addChild:projectile];
    [projectile moveTowardsPosition:position];


}




@end