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 c adalah kelajuan cahaya di udara, agar massa benda menjadi 125 persennya massa diam, benda harus digerakkan pada kelajuan ....
A. 1,25c
B. 1c
C. 0,8c
D. 0,6c
E. 1,5c
Pembahasan :
m = 1,25mo
Jawaban : D
Soal UMPTN 1990/Rayon C - Bila kelajuan partikel 0,6c, maka perbandingan massa relativistic partikel itu terhadap massa diamnya adalah ....
A. 5 : 3
B. 25 : 9
C. 5 : 4
D. 25 : 4
E. 8 : 5
Pembahasan :
Jawaban : C
A. 1,25c
B. 1c
C. 0,8c
D. 0,6c
E. 1,5c
Pembahasan :
m = 1,25mo
Jawaban : D
Soal dan Pembahasan Relativitas
Soal UMPTN 1990/Rayon C - Bila kelajuan partikel 0,6c, maka perbandingan massa relativistic partikel itu terhadap massa diamnya adalah ....
A. 5 : 3
B. 25 : 9
C. 5 : 4
D. 25 : 4
E. 8 : 5
Pembahasan :
Jawaban : C
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