Imagine a particle of mass m, constrained to move along the x-axis, subject to some specified force F(x, t). The program of classical mechanics is to deter- mine the position of the particle at any given time: x(t). Once we know that, we can figure out the velocity (\( v=\frac{dx}{dt}\) ), the momentum (p = mv), the kinetic energy ( \( T=\frac{1}{2}mv^2 \) ), or any other dynamical variable of interest. And how do we go about determining x(t)? We apply Newton's second law: F = ma. (For conservative systems the only kind we shall consider, and, fortunately, the only kind that occur at the microscopic level---the force can be expressed as the derivative of a potential energy function, \( F=-\frac{\partial V}{\partial x} \) , and Newton's law reads \( m\frac{d^2x}{dt^2}=-\frac{\partial V}{\partial x} \) .) This, together with appropriate initial conditions (typically the position and velocity at t 0), determines x(t). Quantum mechanics approaches this same problem quite differentl...
Jika massa proton, neutron, dan partikel α masing-masing 1,007 sma, 1,008 sma, dan 4,002 sma (1 sma = 931 MeV), energi ikat yang dihasilkan oleh partikel α adalah ....
A. 24,068 MeV
B. 25,068 MeV
C. 26,068 MeV
D. 27,068 MeV
E. 28,068 MeV
Pembahasan :
m_n)-m_{inti}&space;\\&space;&=&space;(2\cdot&space;1,007&space;+&space;2\cdot&space;1,008)-4,002&space;\\&space;&=&space;4,03-4,002&space;\\&space;&=&space;0,028&space;\quad&space;\textrm{sma}&space;\end{align*} "\begin{align*} \Delta m &= (Zm_p + (A-Z)m_n)-m_{inti} \\ &= (2\cdot 1,007 + 2\cdot 1,008)-4,002 \\ &= 4,03-4,002 \\ &= 0,028 \quad \textrm{sma} \end{align*}")
Jawaban : C
Jika diketahui inti = 14,0075 sma, massa proton = 1,0080 sma, dan massa neutron = 1,0090 sma, besar defek massanya adalah ....
A. 0,0080 sma
B. 0,0090 sma
C. 0,0175 sma
D. 0,1115 sma
E. 0,1750 sma
Pembahasan :
\cdot&space;m_n)&space;-&space;m_{inti}&space;\\&space;&=&space;(7\cdot&space;1,0080&space;+7\cdot&space;1,0090)&space;-&space;14,0075&space;\\&space;&=&space;14,119&space;-&space;14,0075&space;\\&space;&=&space;0,1115&space;\quad&space;\textrm{sma}&space;\end{align*} "\begin{align*} \Delta m &= (Z\cdot m_p +(A-Z)\cdot m_n) - m_{inti} \\ &= (7\cdot 1,0080 +7\cdot 1,0090) - 14,0075 \\ &= 14,119 - 14,0075 \\ &= 0,1115 \quad \textrm{sma} \end{align*}")
Jawaban : D
A. 24,068 MeV
B. 25,068 MeV
C. 26,068 MeV
D. 27,068 MeV
E. 28,068 MeV
Pembahasan :
Jawaban : C
Jika diketahui inti = 14,0075 sma, massa proton = 1,0080 sma, dan massa neutron = 1,0090 sma, besar defek massanya adalah ....
A. 0,0080 sma
B. 0,0090 sma
C. 0,0175 sma
D. 0,1115 sma
E. 0,1750 sma
Pembahasan :
Jawaban : D
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