Periodic MotionA block of mass M is attached to a horizontal spring with force constant k. It is moving with simple harmonic motion of amplitude A.a) Calculate how much of the energy of the motion is kinetic at x= ¼ A.b) If one adds a mass smoothly in a vertical drop at x=A, calculate what happens to A, T, and w.

Respuesta :

Answer:

Explanation:

Given

mass of block is M

Force constant is k

Natural Frequency of oscillation [tex]\omega _n=\sqrt{\frac{k}{m}}[/tex]

Potential Energy at any instant [tex]U=\frac{1}{2}kx^2[/tex]

where x is compression in spring

[tex]U=\frac{1}{2}k(\frac{A}{4})^2[/tex]

[tex]U=\frac{1}{2}k(\frac{A}{16})[/tex]

Total Energy [tex]=\frac{1}{2}kA^2[/tex] when mass is at maximum Position

Total Energy=Kinetic Energy+Potential Energy

kinetic Energy[tex]=\frac{1}{2}kA^2-\frac{1}{32}kA^2[/tex]

Kinetic Energy[tex]=\frac{15}{32}kA^2[/tex]

(b)If one adds a mass smoothly in a vertical drop at [tex]x=A[/tex]

then its amplitude is going to decrease because more mass is added to the system

its natural frequency changed to [tex]\omega _n' =\sqrt{\frac{k}{2M}}[/tex]

so time Period increases because [tex]T\cdot \omega =2\pi [/tex]

[tex]T=\frac{2\pi }{\omega _n'}[/tex]