The turntable below is spinning. Which coin has a greater speed than the penny?

a. the dime
b. the quarter
c. The penny is moving faster than both of the other coins.
c. All three objects are moving at the same speed.

pennyis closest to center
dime in middle
quarter on outer edge

To determine which coin has a greater speed than the penny, we need to understand the concept of speed and the relationship between radius and speed. The speed of an object in circular motion can be defined as the distance traveled per unit of time.

In this case, we have a turntable with three coins: a penny closest to the center, a dime in the middle, and a quarter on the outer edge. Since the turntable is spinning, each coin will have a different speed based on its distance from the center.

To find out which coin has a greater speed, we can consider the relationship between radius and speed in circular motion. The speed of an object in circular motion is inversely proportional to its radius. This means that the farther a coin is from the center, the greater its speed will be.

Based on this concept, we can conclude that the quarter has a greater speed than the penny. Since the quarter is located on the outer edge, it has a larger radius and therefore a greater speed compared to the penny. The dime, being in the middle, may have a speed between that of the penny and the quarter, but without additional information, we cannot determine its speed relative to the other two coins.

So the correct answer is:

b. the quarter