Final answer:
The gravitational force exerted on a 74.2 kg person standing on Earth's surface is 727.2 N.
Step-by-step explanation:
The gravitational force exerted on a 74.2 kg person standing on Earth's surface can be calculated using Newton's universal law of gravitation. The formula is given as:
F = (G * M * m) / (r^2)
Where F is the gravitational force, G is the gravitational constant (6.674 × 10^-11 N·m² kg^2), M is the mass of the planet (5.97 × 10^24 kg), m is the mass of the person (74.2 kg), and r is the distance from the center of the planet (6.39 × 10^6 m).
Plugging in the values:
F = (6.674 × 10^-11 N·m² kg^2 * 5.97 × 10^24 kg * 74.2 kg) / (6.39 × 10^6 m)^2
After calculating, the answer is 727.2 N, which corresponds to option a).