Ciara is swinging a 0.015 kg ball tied to a string around her head in a flat, horizontal circle. The radius of the circle is 0.50 m. It takes the ball 0.70 seconds to complete one full circle. Calculate the tension in the string and its direction that provides the centripetal force acting on the ball to keep it in the circular path. (3 points)
0.60 N, along the line tangent to the circle
0.015 N, along the line tangent to the circle
0.60 N, toward the center of the circle
0.015 N, toward the center of the circle