-Finally got vectors to work (for velocity and the forces)
Apparently the velocity.x and velocity.y were not setup in the first place
(still not sure why) but by setting them before using them
(getVelocity()*cos(angle)) drifting effect is finally removed.
-Need to fix decelerate(). Problem now is that when we accelerate and then
press DOWN to decelerate, the velocity does not decrease to 0 but merely
changes angle 180 degrees and continues increasing to max velocity.