An oscillating bock-spring system has a mechanical energy of 1.0 J, an amplitude of 0.10 m, and a maximum speed of 1.2 m/s. Find (a) the force constant of the spring, (b) the mass, and (c) the frequency of oscillation.

Respuesta :

Answer:

a) [tex]k = 200.016\,\frac{N}{m}[/tex], b) [tex]m = 1.389\,kg[/tex], c) [tex]f = 0.524\,hz[/tex]

Explanation:

a) The maximum speed of the oscillating block-spring system is:

[tex]v_{max} = \omega \cdot A[/tex]

The angular frequency is:

[tex]\omega = \frac{v_{max}}{A}[/tex]

[tex]\omega = \frac{1.2\,\frac{m}{s} }{0.1\,m}[/tex]

[tex]\omega = 12\,\frac{rad}{s}[/tex]

The mass of the system is:

[tex]E = \frac{1}{2}\cdot m\cdot v_{max}^{2}[/tex]

[tex]m = \frac{2\cdot E}{v_{max}^{2}}[/tex]

[tex]m = \frac{2\cdot (1\,J)}{(1.2\,\frac{m}{s} )^{2}}[/tex]

[tex]m = 1.389\,kg[/tex]

The spring constant is:

[tex]\omega = \sqrt{\frac{k}{m} }[/tex]

[tex]k = \omega^{2}\cdot m[/tex]

[tex]k = (12\,\frac{rad}{s} )^{2}\cdot (1.389\,kg)[/tex]

[tex]k = 200.016\,\frac{N}{m}[/tex]

b) The mass is:

[tex]m = 1.389\,kg[/tex]

c) The frequency of oscillation is:

[tex]\omega = 2\pi\cdot f[/tex]

[tex]f = \frac{2\pi}{\omega}[/tex]

[tex]f = \frac{2\pi}{12\,\frac{rad}{s} }[/tex]

[tex]f = 0.524\,hz[/tex]

Answer:

a) F = 20 N

b) m = 1.39 kg

c) f = 1.909 Hz

Explanation:

Given

E = 1 J

A = 0.1 m

vmax = 1.2 m/s

a) F = ?

b) m = ?

c) f = ?

Solution

a) We apply the equation

E = 0.5*k*A²

then

k = 2*E/A²

k = 2*1 J/(0.1 m)²

k = 200 N/m

then we use the equation

F = kA

F = (200 N/m)(0.1 m)

F = 20 N

b) We use the formula

E = K + U

if U = 0 J

then

E = K = 0.5*m*v²

⇒  m = 2*K/v²

m = 2*1 J/(1.2 m/s)²

m = 1.39 kg

c) we apply the equation

f = (1/2π)√(k/m)

then

f = (1/2π)√(200 N/m/1.39 kg)

f = 1.909 Hz