brodidit for students
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گیارہویں جماعت · طبیعیات · 8 سوالات
نام: ____________________ تاریخ: ____________
In simple harmonic motion the acceleration is proportional to:
- A The displacement, directed to the mean position
- B The velocity
- C The time
- D The mass only
The time period of a mass m on a spring of constant k is:
- A 2 pi sqrt(m / k)
- B pi sqrt(m / k)
- C 2 pi m k
- D 2 pi sqrt(k / m)
A pendulum has period 2 s. What is its length? (g = pi squared, about 9.87 m/s²)
- A 1 m
- B 2 m
- C 0.5 m
- D 4 m
At the mean position of SHM, the speed is:
- A Constant
- B Zero
- C Half of maximum
- D Maximum
Resonance occurs when the driving frequency equals the:
- A Zero
- B Natural frequency
- C Half the natural frequency
- D Double the natural frequency
The total energy of a body in SHM is proportional to the square of its:
- A Time
- B Amplitude
- C Frequency only
- D Mass only
Damped oscillations have an amplitude that:
- A Increases with time
- B Stays constant
- C Doubles each cycle
- D Decreases with time
The frequency of a vibrating system is 5 Hz. Its period is:
- A 25 s
- B 0.5 s
- C 0.2 s
- D 5 s
جوابی کلید
1. A, 2. A, 3. A, 4. D, 5. B, 6. B, 7. D, 8. C
a = -omega2 x.
T = 2 pi times the square root of (m / k).
T = 2 pi sqrt(L / g). With g = π², T = 2 sqrt(L), so L = 1 m.
Speed is greatest at the mean position and zero at the extremes.
When the two match, the amplitude becomes large.
E = 1/2 k A².
Friction removes energy.
T = 1 / f = 0.2 s.