posted by morgan .
A football is kicked at a velocity of 10.5 m/s, 45 degrees above the horizon. After the ball has traveled only horizontally 3.5 m, a member of the opposing team manages to tip the ball with a velocity of 4.5 m/s at an angle of 70 degrees above the horizon. What is the resultant vector of the ball after the tip?
You have just said what the vector (velocity) of the ball is just after the tip. (4.5 m/s at an angle of 70 degrees above the horizon)
What "resultant vector" are you talking about?
Before it is tipped, its vector velocity will have changed due to the action of gravity.