Impulse/momentum check

  • Thread starter DollarBill
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In summary, impulse is the product of force and time, while momentum is the product of mass and velocity. They are directly proportional to each other and the impulse-momentum theorem states that the change in momentum of an object is equal to the impulse applied to it. This theorem is commonly used in sports, such as in baseball. In terms of collisions, in an elastic collision both momentum and kinetic energy are conserved, while in an inelastic collision only momentum is conserved. However, the total impulse remains the same in both types of collisions.
  • #1
DollarBill
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Homework Statement


http://img401.imageshack.us/img401/46/impulsemw6.jpg [Broken]

Before the force is applied (t<0), the particle moves along the x-axis with a velocity of -6.3 m/s.

Find the velocity of the particle after the force stops acting on it.

The particle has a mass of 5.2 kg

Homework Equations


j=[tex]\Delta[/tex]p
[tex]\Delta[/tex]p=0

The Attempt at a Solution


j=42Ns

j=[tex]\Delta[/tex]p
42=mvF-mv0
42=(5.2)vF-5.2(-6.3)
9.24=5.2(v)F
vF=1.777 m/s
 
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  • #2
Your method looks good.
 
  • #3


My response:

Based on the given information, it appears that the particle experiences a force of 42 N for a period of time (t>0) causing a change in its momentum. Using the equation j=\Deltap, we can calculate the change in momentum to be 42 Ns. Since the impulse is equal to the change in momentum, we can then use the equation \Deltap=mvF-mv0 to solve for the final velocity (vF) of the particle. Substituting the given values for mass (m=5.2 kg) and initial velocity (v0=-6.3 m/s), we can solve for vF to be approximately 1.777 m/s. This means that after the force stops acting on the particle, it will continue to move along the x-axis with a velocity of 1.777 m/s. It is important to note that this calculation assumes that there are no other external forces acting on the particle, and that the force applied is constant and in the same direction as the initial velocity.
 

1. What is the definition of impulse and momentum?

Impulse is the product of force and time, while momentum is the product of mass and velocity.

2. How are impulse and momentum related?

Impulse and momentum are directly proportional to each other. This means that an increase in impulse will result in an increase in momentum, and vice versa.

3. What is the impulse-momentum theorem?

The impulse-momentum theorem states that the change in momentum of an object is equal to the impulse applied to it. This can be expressed in the equation: F * t = m * Δv, where F is the force applied, t is the time of application, m is the mass of the object, and Δv is the change in velocity.

4. How is the impulse-momentum theorem applied in real-life situations?

The impulse-momentum theorem is commonly used in sports, such as in baseball when a player hits a ball with a bat. The force of the bat hitting the ball over a short period of time results in a change in the ball's momentum, causing it to travel at a higher velocity.

5. What is the difference between elastic and inelastic collisions in terms of impulse and momentum?

In an elastic collision, both momentum and kinetic energy are conserved, while in an inelastic collision, only momentum is conserved. This means that in an inelastic collision, some of the kinetic energy is lost as heat or sound, resulting in a decrease in the final velocity compared to an elastic collision. However, the total impulse remains the same in both types of collisions.

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