To understand the relationship between force, impulse, and momentum. the effect of a net force σf⃗ acting on an object is related both to the force and to the total time the force acts on the object. the physical quantity impulse j⃗ is a measure of both these effects. for a constant net force, the impulse is given by j⃗ =f⃗ δt. the impulse is a vector pointing in the same direction as the force vector. the units of j⃗ are n⋅s or kg⋅m/s. recall that when a net force acts on an object, the object will accelerate, causing a change in its velocity. hence the object's momentum (p⃗ =mv⃗ ) will also change. the impulse-momentum theorem describes the effect that an impulse has on an object's motion: δp⃗ =j⃗ =f⃗ δt. so the change in momentum of an object equals the net impulse, that is, the net force multiplied by the time over which the force acts. a given change in momentum can result from a large force over a short time or a smaller force over a longer time.

now assume that the pitcher in part d throws a 0.145 kg baseball parallel to the ground with a speed of 20.0 m/s in the -x direction. the batter then hits the ball so it goes directly back to the pitcher along the same straight line. what is the ball's x-component of velocity just after leaving the bat if the bat applies an impulse of +6.9n⋅s to the baseball? enter your answer numerically in meters per second using two significant figures.