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Zorluk: ZorSimple Harmonic Motion

A 0.50 kg0.50\text{ kg} mass attached to a horizontal spring undergoes simple harmonic motion on a frictionless surface. The total mechanical energy of the system is 0.16 J0.16\text{ J} and the force constant of the spring is 32 N/m32\text{ N/m}. What is the speed of the mass, in m/s\text{m/s}, at the instant when the magnitude of its acceleration is 3.84 m/s23.84\text{ m/s}^2?

Cevap: 0.64 m/s

Cevap

The speed of the mass at that instant is 0.64 m/s0.64\text{ m/s}.
Using the relation for total mechanical energy E=12kA2E = \frac{1}{2}kA^2, the amplitude is A=0.10 mA = 0.10\text{ m}. The angular frequency is ω=k/m=8.0 rad/s\omega = \sqrt{k/m} = 8.0\text{ rad/s}. From a=ω2x|a| = \omega^2 |x|, the displacement magnitude when acceleration is 3.84 m/s23.84\text{ m/s}^2 is x=0.06 m|x| = 0.06\text{ m}. Substituting these values into v=ωA2x2v = \omega \sqrt{A^2 - x^2} yields v=8.00.1020.062=0.64 m/sv = 8.0 \sqrt{0.10^2 - 0.06^2} = 0.64\text{ m/s}.

Adım Adım Çözüm

1
Calculate the angular frequency of the simple harmonic motion
ω=8.0 rad/s\omega = 8.0\text{ rad/s}
The angular frequency depends on the stiffness constant and the mass according to \omega = \sqrt{k/m}.
2
Calculate the amplitude of oscillation from total energy
A = 0.10\text{ m}
The total mechanical energy in SHM is given by E = \frac{1}{2}kA^2.
3
Find the magnitude of displacement corresponding to the given acceleration
|x| = 0.06\text{ m}
In SHM, acceleration magnitude is related to displacement magnitude by |a| = \omega^2 |x|.
4
Calculate the speed at this displacement using the SHM velocity-displacement relation
v = 0.64\text{ m/s}
Velocity in SHM is calculated using v = \omega \sqrt{A^2 - x^2}.

Anahtar Kavram

Interdependence of energy, angular frequency, acceleration, and velocity in Simple Harmonic Motion
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