The diagram shows a device that uses radio waves.
What is the role of the part in the diagram labeled X?
Х
O modulate, amplify, and send out waves
O capture, amplify, and demodulate waves
O change the amplitude and frequency of waves
o change the pulse and phase of waves

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.