In the overhead view of the figure, a 420 g ball with a speed v of 7.7 m/s strikes a wall at an angle θ of 39∘ and then rebounds with the same speed and angle. It is in contact with the wall for 6.7 ms. In unit-vector notation, what are (a) the impulse on the ball from the wall and (b) the average force on the wall from the ball? (a) Number i + j Units (b) Number i + j Units