Kaplan Nursing Entrance Practice Exam

An astronaut has less of which force when in outer space?

1. Mass

2. Gravity

3. Weight

4. Inertia

The correct answer is: Weight

In outer space, an astronaut experiences less weight due to the significant reduction in the gravitational force acting on them. Weight is defined as the force exerted by gravity on an object and is calculated as the product of mass and the acceleration due to gravity. While the mass of the astronaut remains constant regardless of location, the gravitational force decreases as they move further from a massive body like Earth. In space, especially in a low-gravity environment, this results in a markedly lower experience of weight. This is why astronauts appear to float or are in a state of free-fall when orbiting Earth, despite their mass being unchanged. The other forces mentioned, namely mass and inertia, do not change in gravitational fields. Mass is an intrinsic property of the astronaut and remains constant, while inertia, which is the tendency of an object to resist changes in its state of motion, also remains unaffected. As such, the correct response highlights the unique conditions of outer space and the way they alter the experience of weight.