Four energies arrive in four different units:

PHYSICS · Multi-part · Fermi University Physics · Biophysics & Medical Physics · Physical foundations of the living cell · Physical foundations of the living cell

Life at Thermal Energy, Ch The scales of life and the thermal energy

Problem

Four energies arrive in four different units: (i) a force of

5\,\mathrm{pN}

acting over

8\,\mathrm{nm}

; (ii) a binding energy of

40\,\mathrm{kJ\,mol^{-1}}

; (iii) an ultraviolet photon of wavelength

250\,\mathrm{nm}

; (iv) an energy of

0.05\,\mathrm{eV}

. ((a)) Place each on the chapter's energy ledger in units of

k_BT

298\,\mathrm{K}

, and list them from lowest to highest. ((b)) For each, say which band of the chapter's rule of thumb it falls in: within a few

k_BT

, between about

5

and

20\,k_BT

, or far above

20\,k_BT

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