Final answer:
The ideal time for a skydiver to fall 800 meters under gravity alone is approximately 12.8 seconds, calculated using the formula for free-fall distance.
Correct option is 12.8 sec
Step-by-step explanation:
The question is asking to determine the time it takes for a skydiver to fall 800 meters. This is a classic physics problem involving the equations of motion under the influence of gravity. To solve the problem, we can use the formula \( h = \frac{1}{2}gt^2 \), where h is the height the skydiver falls (800 meters), g is the acceleration due to gravity (approximately 9.8 m/s^2), and t is the time in seconds.
To find t, we rearrange the formula to solve for t: t = \sqrt{(2h)/g}. Substituting the given values, t = \sqrt{(2 \times 800 m)/(9.8 m/s^2)}. Performing the calculation, t \approx 12.8 seconds.
However, this calculation does not account for air resistance, which significantly affects the fall time of a skydiver. In a real-world scenario, the skydiver reaches terminal velocity and the fall time would be longer than the calculated time. The answer choices provided do not correlate directly with our calculation, which indicates that this question may be looking for an idealized scenario or that additional information is required to take air resistance into account.