An astronaut is outside of her spaceship with no jetpack or tie line, repairing the engine. Suddenly, she finds herself away from the ship, and only has a wrench in her hands. As she stares at her ship, she tries to think of a way to get back. Since there is nothing to push off from, she thinks that she may be lost forever, but suddenly remembers the wrench. Using the wrench, how can she get back to the ship? How does this demonstrate Newton’s 1st Law?
by throwing the wrench away from the spaceship , she will give herself momentum towards the ship
to me , this seems more like the 3rd law ... action/reaction
1st law says that unless a force acts, she will stay away from the ship.
To use the wrench to get back to the ship, the astronaut can follow these steps:
1. Hold the wrench tightly in her hand with the handle pointing away from her body.
2. Rotate her body in the opposite direction to the ship, while keeping the wrench still.
3. Due to the conservation of angular momentum, her body will start rotating in the opposite direction to the ship.
4. Gradually, her rotation will cause her to approach the ship.
5. Once she is close enough, she can reach out and grab onto the spaceship to pull herself back inside.
This process demonstrates Newton's First Law of Motion, also known as the law of inertia. Newton's first law states that an object at rest will remain at rest, and an object in motion will continue in motion with a constant velocity, unless acted upon by an external force. In this scenario, the astronaut is initially at rest in space, with no external forces acting on her. When she rotates her body with the wrench, she imparts an angular acceleration to herself. Due to the law of inertia, her body resists changes in its state of rest or motion, and as a result of this resistance, she experiences a reaction force in the opposite direction, propelling her towards the spaceship. The astronaut utilizes this law to propel herself back to the ship and overcome the lack of a jetpack or tie line.
To understand how the astronaut can use the wrench to return back to the spaceship, let's first review Newton's First Law of Motion. Newton's First Law, also known as the law of inertia, states that an object at rest will stay at rest, and an object in motion will stay in motion with the same speed and direction, unless acted upon by an external force.
In this scenario, the astronaut finds herself away from the spaceship with no means of propulsion. However, she has a wrench in her hands. By utilizing the law of inertia, she can manipulate the wrench to create an external force and change her own motion.
The astronaut can hold the wrench out in front of her, away from her body and in the opposite direction of the spaceship. Then, by twisting or rotating her body in the opposite direction, she can exert a force on the wrench. According to Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction, this will cause the wrench to exert an equal and opposite force back on the astronaut.
As a result, due to the conservation of momentum, the astronaut will experience a reactive force propelling her towards the spaceship. By alternating the direction of her rotations and manipulating the wrench, she can continually apply forces to herself, pushing off the wrench and propelling herself closer to the spaceship.
In other words, by using the wrench to generate the external force needed to change her own motion, the astronaut can effectively move herself towards the spaceship and eventually return to it.
This scenario demonstrates Newton's First Law because the astronaut is using the wrench as an external force to act on herself and change her own motion. Without this external force, she would continue moving away from the spaceship due to her initial momentum, in accordance with the law of inertia.