Final answer:
Using the formula for free fall motion, d = (1/2)gt², with g = 9.8 m/s² and t = 40 seconds, the depth of the well is calculated to be 7840 m, indicating a hypothetical scenario. so, option C is the correct answer.
Step-by-step explanation:
To solve for the depth of the well in the student's question on how deep is the well when a penny is dropped from the top and takes 40 seconds to hit the bottom, we use the formula of free fall motion which is d = (1/2)gt², where d is the distance, g is the acceleration due to gravity (approximately 9.8 m/s²), and t is the time it takes for the object to fall. Substituting the given values, we have d = (1/2)(9.8 m/s²)(40 s)². After computing the values, we find that the depth of the well is 7840 m (which appears to be a very unrealistic depth for a well and indicates that the problem is likely hypothetical or that the time given is not accurate for a real-life scenario).
To calculate the depth of the well, we can use the equation for free fall motion: d = 1/2 * g * t^2, where d is the depth of the well, g is the acceleration due to gravity (approximately 9.8 m/s^2), and t is the time it takes for the penny to hit the bottom.
Plugging in the values, we get: d = 1/2 * 9.8 * (40)^2 = 784 meters.
Therefore, the depth of the well is 784 meters.