Question

Which of the following statements is INCORRECT?

• A. Motion cannot be defined without a reference point.
• B. The Earth is moving with respect to a man in space.
• C. With respect to a man on Earth, the Sun is moving.
• D. The Moon is at rest with respect to a man on Earth.

Answer 1

The correct option is D The Moon is at rest with respect to a man on Earth.

To define motion, we need to define 'according to who?'. This means that the concept of motion is meaningless without the reference point.
With respect to a man in space, the Earth seems to be moving around the Sun. Hence, it is true.
With respect to a man on Earth, the Sun moves. That's seen in the form of sunrise and sunset. Hence, this statement is true.

With respect to a man on Earth, the Moon is moving. Hence, the statement "The Moon is at rest with respect to a man on Earth." is incorrect.