An ice skater of mass m skates in a circle of radius R at a constant speed v.

1. The net force on the skater must
   1. be zero
   2. point away from the center of the circle
   3. point towards the center of the circle
2. If the skater speeds up, so that she is again making circles, but now at constant speed 1.5*v, the net force on her
   1. is still zero
   2. must be larger in size
   3. must be smaller in size
3. The skater slips, falls flat on the ice, and slides to the North. The net force on her now
   1. is zero
   2. points to the center of the circle
   3. points North
   4. none of the above