The minute hand of the math wall clock is 5 cm long. What is the distance traveled by the needle tip of the minute hand from 8 am to 8 pm? What is the square area swept by the minute hand?
When the minute hand makes a circle, the distance traveled by the needle tip is the circumference of the circle with a radius of 5cm, that is, 2*3. 14*5=3 1.4, and the swept area is the area of the circle with a radius of 5cm, that is, 3.14 * 5 = 78.5. It takes an hour for the minute hand to turn around, from 8 am to 8 pm.