4) A soccer player kicks a ball, while imparting spin to bend it. The ball starts on the ground and is kicked with an initial velocity of 15 m/s, at an angle of elevation 30 degrees. Assume the ball was kicked north and the spin creates a constant acceleration a to the west, which is what makes the ball follow a curved path. If the ball lands 8 meters west of the starting point, what is the value of a? Assume the standard value of g = 9.8 m/s².

4) A soccer player kicks a ball, while imparting spin to bend it. The ball starts on the ground and is kicked with an initial velocity of 15 m/s, at an angle of elevation 30 degrees. Assume the ball was kicked north and the spin creates a constant acceleration a to the west, which is what makes the ball follow a curved path. If the ball lands 8 meters west of the starting point, what is the value of a? Assume the standard value of g = 9.8 m/s².