A particle has kinetic energy E and de Broglie wavelength λ. How much additional energy must be supplied so that its wavelength becomes 75% of its initial value?
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A particle has kinetic energy E and de Broglie wavelength λ. How much additional energy must be supplied so that its wavelength becomes 75% of its initial value?

G1 Physics · Accepted Answer

Step 1: For fixed mass, λ∝1/√K. Step 2: If λ′=0.75λ, then K′/K=(λ/λ′)²=(4/3)²=16/9. Step 3: Extra energy = K′−K = 7E/9. Correct answer: B.