html5 - Phaser-Projectiles being affected by gravity -

i set gravity 1000 in create function :

game.physics.arcade.gravity.y = 1000; 

but when intergraded projectiles in own function:

function shootr(){     if (canshoot) {         if (attacktimer< game.time.now) {             attacktimer = game.time.now + 500;             var projectile;             projectile = projectiles.create(                 player.body.x + player.body.width  / 2,                 player.body.y + player.body.height / 2,                 'powerball');              game.physics.enable(projectile, phaser.physics.arcade);              projectile.outofboundskill = true;             projectile.anchor.setto(0.5, 0.5);             projectile.body.velocity.x = 400;         }     } }  

the projectile being affected gravity, being dragged ground when projectile being launched. how make shoots in straight line, while other objects shot being affected gravity.