Conservation of Momentum
1. What is a system?
2. How is a closed system different from an open system?
3. How does a newton’s cradle deompstrate conservation of momentum?
4. How does a space shuttle use conservation of momentum to leave earth?
5. Why do astronauts need to be tethered on a space walk?
1. A system refers to a collection of interacting objects or components that are being examined or analyzed. It can be a physical system, such as a group of particles, or a conceptual system, such as a set of equations or principles.
2. In a closed system, no mass or energy is exchanged with its surroundings, meaning that no matter or energy enters or leaves the system. In contrast, an open system allows for the exchange of mass, energy, or both with its surroundings.
3. Newton’s cradle is a device that consists of a row of identical pendulums or spheres suspended from a frame. When one of the spheres at the end is lifted and released to swing back and hit the others, only the sphere on the opposite end moves outward. This demonstrates the conservation of momentum, as the total momentum of the system remains constant throughout the process. The momentum is transferred from one sphere to the next, but the total momentum is conserved.
4. A space shuttle uses conservation of momentum to leave Earth through the use of controlled combustion and ejection of non-recoverable propellant gases from its engines. As the propellant is expelled, it exerts a force on the shuttle in one direction, causing it to accelerate in the opposite direction due to Newton's third law of motion (action-reaction). By continuously expelling propellant gases, the shuttle gradually gains momentum, allowing it to overcome the gravitational pull of Earth and reach space.
5. Astronauts need to be tethered during a spacewalk to ensure their safety and prevent them from floating away into space. In the microgravity environment of space, there is no significant force to counteract their movement, and any initial push or unintended motion can cause them to drift away. Tethering astronauts to the space station or another secure object ensures that they remain safely attached and can be reeled back in if necessary. The tether acts as a connection that aids in controlling and limiting their movement during the spacewalk.