Newtons cradle Conservation of Momentum

J/kg.In summary, The conservation of momentum equation may need to be modified to account for the momentum of the first ball after the collision. Additionally, the equation for conservation of energy should also be written out and used to solve for the velocities of both balls after the collision. It is important to note that the height of the second ball may be less than the initial height due to the conversion to SI units for the numerical answer.
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You have the general idea but the conservation of momentum equation needs a bit of modification. The momentum before is correct but the momentum after forgets the momentum of the first ball. It might turn out the the momentum of the first ball is 0 after the collision but this should come from the algebra. Also, write out the equation of conservation of energy. Then you have two equations with two unknowns (velocity of ball 1 and velocity of ball 2 both after the collision). Finally, why do you say that the height of the second ball is less than the initial height?

One last thing, it might help to convert your number to SI units for numerical answer e.g. the potential energy isn't actually 14700J
 

Related to Newtons cradle Conservation of Momentum

1. How does Newton's cradle demonstrate the conservation of momentum?

Newton's cradle is a classic demonstration of the conservation of momentum, which states that in a closed system, the total momentum before a collision is equal to the total momentum after the collision. In the case of the cradle, when one ball is dropped and collides with the stationary balls, the momentum is transferred through the balls, causing the last ball to swing up with the same force as the first ball. This demonstrates the conservation of momentum, as the total momentum before and after the collision remains the same.

2. What is the significance of the constant swinging motion in Newton's cradle?

The constant swinging motion in Newton's cradle is a result of the conservation of energy. The balls act as pendulums, with kinetic energy being transferred between them as they collide. Since energy cannot be created or destroyed, the motion of the balls will continue until friction or air resistance brings it to a stop.

3. Can the number of balls in a Newton's cradle affect the conservation of momentum?

Yes, the number of balls in a Newton's cradle can affect the conservation of momentum. The more balls there are, the longer the transfer of momentum will take. This is because each collision between the balls will slightly decrease the total momentum, causing the last ball to swing with less force. However, as long as the system remains closed and there is no external force acting on it, the conservation of momentum will still hold true.

4. How does the material of the balls in a Newton's cradle affect its behavior?

The material of the balls in a Newton's cradle can affect its behavior in terms of the speed and duration of the swinging motion. Heavier balls will have more momentum and cause the last ball to swing with more force. Lighter balls will have less momentum and cause the last ball to swing with less force. The material can also affect the amount of friction and air resistance, which can impact the duration of the swinging motion.

5. Can Newton's cradle be used to demonstrate other laws of physics?

Yes, Newton's cradle can be used to demonstrate other laws of physics, such as the conservation of energy and the laws of motion. It can also be used to illustrate concepts like impulse and elastic collisions. However, it is important to note that Newton's cradle is a simplified model and may not accurately represent all aspects of these laws and concepts.

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