Question
Question: A 200g cricket ball is thrown with a speed of \(3.0 \times {10^3}cm/s\). What will be its de Broglie...
A 200g cricket ball is thrown with a speed of 3.0×103cm/s. What will be its de Broglie’s wavelength?
(h=6.6×10−27gcm2sec−1)
a.) 1.1×10−32cm
b.) 2.2×10−32cm
c.) 0.55×10−32cm
d.) 11.0×10−32cm
Solution
Hint: This question can be solved by using the de Broglie equation, that is λ=mvh , where h is the Planck's constant, λ is the de Broglie wavelength and m is the mass of the particle moving at a velocity v .
Complete step-by-step answer:
Given in the question that the speed of the ball i.e. v is 3.0×103cm/s. Also given the mass i.e. m is 200g and the value of planck's constant h=6.6×10−27gcm2sec−1.
De Broglie’s equation relates a moving particle’s wavelength to its momentum. The equation, therefore becomes, λ=ph , where h is the Planck's constant, and p is the momentum of the particle. The momentum of any object or particle is given by p=mv . Therefore, the de Broglie equation becomes λ=mvh.
Substituting the values of planck's constant, mass and velocity in the de Broglie equation, i.e. λ=mvh, we get
⇒λ=200g×3×103cm/s6.6×10−27gcm2sec−1
Further simplifying,
⇒λ=2002.2×10−30cm
⇒λ=1.1×10−32cm
Hence, de Broglie’s wavelength is calculated to be 1.1×10−32cm.
Therefore, option A is correct.
Note- de Broglie’s equation describes the wave property of matter, especially the wave nature of electrons. De Broglie suggested that a particle can exhibit properties of a wave. The matter has a dual nature. This is also known as de Broglie hypothesis. De Broglie wavelength is a wavelength exhibited in all the objects in quantum physics which establishes the probability density of discovering the object at a given point of the arrangement space. The de Broglie wavelength of a particle is inversely proportional to its momentum.