You throw a ball off the top of a 4.20 m high building. When you let the ball go, it is traveling with a speed of 18.0 m/s in the direction 37.0 above the horizontal. The ball hits the ground traveling with a speed of 20.2 m/s. Let the +x direction point in the direction you threw the ball and the +y direction point up.

(a) Using the given coordinate system, what is the sign of the x-component of the final velocity of the ball when it hits the ground?

• Negative
• Zero
• Positive

(b) Using the given coordinate system, what is the sign of the y-component of the final velocity of the ball when it hits the ground?

• Negative
• Zero
• Positive