Vibrations: A momentum impulse starts a mass into oscillatory motion

AI Thread Summary
A sudden momentum impulse refers to an instantaneous application of force that sets the mass in motion, transitioning it from rest to a nonzero velocity. In the context of the problem, this impulse is applied at time t=0, and after this moment, no external forces act on the system. The correct equation of motion for the system is md²x/dt² - kx = 0, indicating simple harmonic motion. The initial velocity of the mass after the impulse is calculated as v1 = p1/m. The system can be analyzed using initial conditions for position and velocity to determine the amplitude and phase constant of the oscillation.
Zamarripa
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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.
 
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Zamarripa said:
don't understand what does "a sudden momentum impulse" means
It means going suddenly from rest to moving at some nonzero velocity.
 
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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.
 
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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?
 
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.
 
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