Sven hits a baseball (m = 0.15 kg). He applies an average force of 54.0 N. The ball had an initial velocity of 36.0 m/s to the right and a final velocity of 42.0 m/s to the left as viewed by a fan in the stands.

(a) What is the impulse delivered by Sven's bat to the baseball? (Assume to the right as viewed by the fan is positive. Indicate the direction with the sign of your answer.)

(b) How long is his bat in contact with the ball?