# Quick question about universal gravitation collisions.

• xoombot
U1 is asking if when two masses collide, will they have the same velocities or will it depend on the conserved momentum if there are no external forces acting on the system. This question is in reference to a problem that assumes the masses are released from rest. In summary, AMbU1 is wondering about the velocities of two colliding masses in a system with no external forces, assuming they are released from rest.

#### xoombot

When two masses collide, assuming there are no external forces on the system of the two masses, will they collide with the same velocities or will it depend on the conserved momentum?

Edit -- Assume they're released from rest, since that's what the problem I'm working on states.

Last edited:
xoombot said:
When two masses collide, assuming there are no external forces on the system of the two masses, will they collide with the same velocities or will it depend on the conserved momentum?

Edit -- Assume they're released from rest, since that's what the problem I'm working on states.
You will have to explain the whole problem. Your question is not understandable.

AM

Great question! The answer depends on the conservation of momentum in the system. In the absence of external forces, the total momentum of the system (the two masses) will remain constant. This means that the initial momentum of the two masses before the collision will be equal to the final momentum after the collision.

If the two masses are released from rest, their initial momentum will be zero. This means that after the collision, their final momentum will also be zero. However, this does not necessarily mean that they will have the same velocities. The final velocities of the two masses will depend on their respective masses and the nature of the collision (elastic or inelastic).

In an elastic collision, both the total momentum and the total kinetic energy of the system are conserved. In this case, the two masses will collide with equal and opposite velocities, resulting in a symmetrical rebound. However, in an inelastic collision, some of the kinetic energy will be lost and the masses may not collide with the same velocities.

So, to answer your question, the final velocities of the two masses after the collision will depend on the conservation of momentum and the nature of the collision. I hope this helps! Let me know if you have any further questions.

## 1. What is universal gravitation?

Universal gravitation is a physical principle that describes the mutual attraction between all objects with mass in the universe. It was first discovered by Sir Isaac Newton and is represented by the famous equation F = G(m1m2)/r^2, where F is the force of gravity, G is the universal gravitational constant, m1 and m2 are the masses of the two objects, and r is the distance between them.

## 2. What is a collision in the context of universal gravitation?

A collision in the context of universal gravitation occurs when two objects with mass come into contact or interact with each other due to the force of gravity. This can result in changes in the motion, direction, or shape of the objects involved.

## 3. How is universal gravitation related to collisions?

Universal gravitation plays a crucial role in determining the outcome of collisions between objects with mass. The force of gravity between the two objects will affect their velocities and trajectories, and can ultimately determine whether the collision is elastic or inelastic.

## 4. What are elastic and inelastic collisions?

An elastic collision is one in which the total kinetic energy of the objects involved is conserved. In an inelastic collision, some of the kinetic energy is converted into other forms of energy, such as heat or sound. The outcome of a collision can be determined by the relative masses and velocities of the objects, as well as the force of gravity between them.

## 5. How does the distance between objects affect collisions in universal gravitation?

The distance between objects is a crucial factor in determining the strength of the force of gravity and therefore the outcome of a collision. As the distance between objects increases, the force of gravity decreases, resulting in a weaker collision. Conversely, a smaller distance will result in a stronger collision due to a greater force of gravity.