5. To impress the class, a physics teacher uses a pail filled with water attached to a rope in a classic physics demonstration. The teacher then whirls the pail in a vertical circle. If the length of the rope from her hand to the centre of the pail is 1.25 m, how slow can she swing the pail to complete the circle? Justify your answer fully. Make sure to draw a free-body diagram of the pail. [3 marks]