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? asked in Science & MathematicsPhysics · 1 decade ago

show that the famous 'Einstein equation' E=mc^2 is dimentionally consistent?

6 Answers

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  • ?
    Lv 7
    1 decade ago
    Favorite Answer

    The fundamental units are mass, length & time:

    E = F*L = m*a*L = m*(L/t²)*L = m*(L²/t²)

    mc² = m*(L²/t²)

    QED

  • 1 decade ago

    show that the famous 'Einstein equation' E=mc^2 is dimentionally consistent?

    E = mass * c^2

    E = energy

    m = mass = kg

    c = speed of light = 3 * 10^8 m/s

    c^2 = m^2 / s^2

    mc^2 = kg * m^2/s^2

    The unit of energy = Joule = Newton * meters

    Newton is unit of Force, F = mass * a

    Mass = kg, a = m/s^2, so F = kg * m /s^2

    Joule = Newton * m = kg * m /s^2 * m

    Joule = kg * m^2 /s^2

    mc^2 = kg * m^2/s^2

    Units agree

  • 1 decade ago

    Since the question is whether the equation is dimensionally correct? we need not analyse it dimensionally. It is enough, if the left and right side of this equation represents the same physical quantity.

    L.H.S is energy.

    R.H.S is mass times square of velocity which is kinetic energy and hence energy.There are no other quantity in the right side other than energy.

    Hence it is dimensionally correct.

    ======================================

  • 1 decade ago

    sure, same as kinetic energy = 1/2 mv^2

    m is in kg

    v is in m/s

    so mc^2 has the same units as 1/2 mv^2 Both are in kg*m^2/s^2 which is a Joule, the standard unit of energy (E)

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  • 4 years ago

    The unit of energy = Joules =Nm

    As,Energy =F×L

    Dimensions of l.h.s of eq.= [E]= [ML^2 T^-2]

    Dimensions of r.h.s of the eq. = [ML^2 T ^-2]

    SINCE lhs = rhs

    Eq is dimensionally consistent

  • Anonymous
    1 decade ago

    Use dimensional analysis and the base units for M, L, T.

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