One of the events in the Scottish Highland Games is the sheaf toss, in which a 7.95-kg bag of hay is tossed straight up into the air using a pitchfork. During one throw, the sheaf is launched straight up with an initial speed of 2.45 m/s. a) What is the impulse exerted on the sheaf by gravity during the upward motion of the sheaf (from launch to maximum height)