Final answer:
Anna is correct; a satellite in orbit is in free fall because it is continuously falling toward Earth, though it has enough horizontal velocity to remain in orbit. The value of gravitational acceleration being less than 9.80 m/s² at altitude does not negate the state of free fall. Option a) Anna; gravity causes free fall is the correct answer.
Step-by-step explanation:
When discussing the state of satellites in orbit, it's important to understand the nature of free fall and how gravity acts on objects in space. Despite the common association of free fall with the acceleration due to gravity being 9.80 m/s² at Earth's surface, free fall is defined as any motion of a body where gravity is the only force acting upon it. Therefore, Anna is correct when she says a satellite is in free fall because it is continuously falling toward Earth; however, its horizontal velocity is large enough to ensure that it keeps missing the Earth. This gives the effect of orbiting around the planet. The value of 'g' being different (less than 9.80 m/s²) at the altitude of satellites doesn't negate the state of free fall; instead, it indicates that gravitational force decreases with distance from the Earth's surface.
Tom incorrectly assumes that free fall must involve the Earth's surface acceleration value of 'g'. The essence of free fall is not dependent on this specific value but on the presence of gravitational pull as the sole force. Effectively, Tom's reference to the differing values of 'g' at higher altitudes is not sufficient to dispute the satellite's free fall status. Therefore, mentioning the correct option in the final answer, we choose only one option: (a) Anna is correct; gravity causes free fall. Satellites in orbit are indeed in a state of free fall, as they are being pulled by Earth's gravity, causing them to perpetually fall towards the planet, yet having sufficient tangential velocity to keep missing it.