(Solved): 1. A tennis ball is tied to one end of a string. The string is threaded through a pipe and the othe ...

1. A tennis ball is tied to one end of a string. The string is threaded through a pipe and the other end is attached to a mass as shown in the figure. You are holding the pipe and swinging the ball in a circle, just so that the mass $M$ does not rise or sink, and the paper clip is not quite touching the pipe. As you swing the ball at this speed, it will move in a circular path of constant radius. (a) How many forces are acting on the ball? Draw a free-body diagram and explain each force. (b) Is the net force on the ball zero? How do you know? 2. If the net force on the ball is not zero, it must accelerate. What does this mean? How can an object accelerate without changing its speed? 3. In the figure above, the ball of mass $m$ moves in a circle. Indicate where the center of this circle is located using a penciled in $x$ on the figure. 4. If an object moves at constant speed $v$ around a circle of radius $r$, what is the magnitude $a=?\vec{a}?$ of its acceleration, and toward what place does the acceleration vector, $\vec{a}$, always point?