Two equal mass train cars move towards each other at the same speed. They link together and both stop moving at that point they collide. How can this be true if momentum must to be conserved.
Gravitational force
In nature, every object is attracted by every other object. This phenomenon is called gravity. The force associated with gravity is called gravitational force. The gravitational force is the weakest force that exists in nature. The gravitational force is always attractive.
Acceleration Due to Gravity
In fundamental physics, gravity or gravitational force is the universal attractive force acting between all the matters that exist or exhibit. It is the weakest known force. Therefore no internal changes in an object occurs due to this force. On the other hand, it has control over the trajectories of bodies in the solar system and in the universe due to its vast scope and universal action. The free fall of objects on Earth and the motions of celestial bodies, according to Newton, are both determined by the same force. It was Newton who put forward that the moon is held by a strong attractive force exerted by the Earth which makes it revolve in a straight line. He was sure that this force is similar to the downward force which Earth exerts on all the objects on it.
![**Question 6:**
Two equal mass train cars move towards each other at the same speed. They link together and both stop moving at that point they collide. How can this be true if momentum must to be conserved?
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**Explanation:**
In this scenario, two train cars with equal mass are moving directly towards each other at the same speed. When these cars collide, they link together and come to a complete stop. According to the principle of conservation of momentum, the total momentum of a system remains constant if no external forces are acting on it.
Here's a breakdown of why this situation doesn't violate the conservation of momentum:
1. **Initial Momentum Calculation:**
- Let the mass of each train car be \( m \).
- Let the speed of each train car be \( v \).
- The momentum of one train car is \( mv \).
- The momentum of the other train car is \( -mv \) (opposite direction).
- Total initial momentum = \( mv + (-mv) = 0 \).
2. **Final Momentum Calculation:**
- After the collision, the linked train cars have zero velocity.
- Total final momentum = \((m+m) \times 0 = 0\).
Therefore, the total momentum before and after the collision is zero, satisfying the conservation of momentum. The cars stop because their momenta cancel each other out perfectly.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F0ee67c44-0754-41fd-9006-bdc882dbaccb%2Fa9d4d2d8-b03b-4af5-8b7d-ca3655f97f81%2Fi38owh_processed.jpeg&w=3840&q=75)
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Law of conservation of momentum:-
- According to the rule of conservation of momentum, absent an external force, the combined momentum of two or more bodies operating upon one another in an isolated system remains constant.
- As a result, momentum cannot be gained or lost.
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