Vibrations: A momentum impulse starts a mass into oscillatory motion

In summary, the problem involves a system at rest that is set into vibration by a sudden momentum impulse to the left. The resulting motion can be described by the equation md^2x/dt^2+dp1/dt-kx=0, with initial conditions x(t=0)=x0 and v(t=0)=v1. This problem is from the book Vibrations and Waves in physics by Ian Main.
  • #1
Zamarripa
11
0
Homework Statement
The system shown at rest in fig 1.1(a) could be set into vibration by giving the mass a sudden momentum impulse to the left:by trapping it with a hammer, for example. If the magnitude of the impulse is p1 and its given at time t=0, find (a) the amplitude and (b) the phase constant of the ensuing motion.
Relevant Equations
md^2x/dt^2-kx=0
The fig. 1.1(a) is a mass m attached to a spring that is fixed to a wall. I don't understand what does "a sudden momentum impulse" means. Is it an external force o what?
I imagined that the new equation of motion would be

md^2x/dt^2+dp1/dt-kx=0

md^2x/dt^2+mdv1/dt-kx=0

is this the equation i have to solve?

The problem is from the book Vibrations and Waves in physics from Ian Main.
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
Zamarripa said:
don't understand what does "a sudden momentum impulse" means
It means going suddenly from rest to moving at some nonzero velocity.
 
  • Like
Likes Zamarripa
  • #3
Zamarripa said:
Problem Statement: The system shown at rest in fig 1.1(a) could be set into vibration by giving the mass a sudden momentum impulse to the left:by trapping it with a hammer, for example. If the magnitude of the impulse is p1 and its given at time t=0, find (a) the amplitude and (b) the phase constant of the ensuing motion.
Relevant Equations: md^2x/dt^2-kx=0

The fig. 1.1(a) is a mass m attached to a spring that is fixed to a wall. I don't understand what does "a sudden momentum impulse" means. Is it an external force o what?
I imagined that the new equation of motion would be

md^2x/dt^2+dp1/dt-kx=0

md^2x/dt^2+mdv1/dt-kx=0

is this the equation i have to solve?

The problem is from the book Vibrations and Waves in physics from Ian Main.
The '"sudden momentum impulse" certainly means that the mass is given momentum by a sudden impulse p1 at t=0. Except for the initial moment, there is no external force.
What is the initial velocity of the vibration then?
Check the relevant equation, it is not correct.
 
  • Like
Likes Zamarripa
  • #4
ehild said:
The '"sudden momentum impulse" certainly means that the mass is given momentum by a sudden impulse p1 at t=0. Except for the initial moment, there is no external force.
What is the initial velocity of the vibration then?
Check the relevant equation, it is not correct.
The initial velocity is v1=p1/m and the problem is just a simple harmonic oscillation with initial conditions x(t=0)=x0, v(t=0)=v1?
 
  • #5
Zamarripa said:
The initial velocity is v1=p1/m and the problem is just a simple harmonic oscillation with initial conditions x(t=0)=x0, v(t=0)=v1?
Yes.
 
  • Like
Likes Zamarripa

1. What is meant by "Vibrations" in relation to momentum impulse and oscillatory motion?

Vibrations refer to periodic or repetitive motions of an object around a stable equilibrium point. In the context of momentum impulse and oscillatory motion, vibrations occur when a force is applied to an object, causing it to move back and forth around its equilibrium point.

2. How does a momentum impulse start a mass into oscillatory motion?

A momentum impulse occurs when a force is applied to an object over a short period of time, resulting in a change in the object's momentum. This change in momentum causes the object to start moving, and if the force is applied in a periodic manner, the object will continue to oscillate back and forth around its equilibrium point.

3. What factors affect the frequency of vibrations in this scenario?

The frequency of vibrations in this scenario is affected by the mass of the object, the amplitude of the oscillations, and the stiffness of the object. Heavier objects will have a lower frequency, while objects with higher stiffness will have a higher frequency. The amplitude of the oscillations also plays a role, with larger amplitudes resulting in lower frequencies.

4. Can vibrations be harmful to objects or structures?

Yes, vibrations can be harmful to objects and structures if they are not properly designed to withstand them. Excessive vibrations can lead to fatigue and damage in the materials, which can ultimately result in failure of the object or structure.

5. How are vibrations useful in everyday life?

Vibrations have many practical applications in everyday life, such as in musical instruments, engines, and electronics. They are also used in earthquake-resistant building designs and in medical devices such as ultrasound machines. Additionally, vibrations play a crucial role in our sense of touch, allowing us to feel textures and vibrations through our skin.

Similar threads

  • Introductory Physics Homework Help
Replies
15
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
24
Views
2K
  • Introductory Physics Homework Help
Replies
17
Views
376
  • Introductory Physics Homework Help
Replies
30
Views
2K
  • Introductory Physics Homework Help
Replies
6
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
24
Views
2K
  • Introductory Physics Homework Help
Replies
7
Views
5K
Back
Top