Question 123: Dual Nature of Matter and Radiation

Question

A small object at rest, absorbs a light pulse of power $$20 \mathrm{~mW}$$ and duration $$300 \mathrm{~ns}$$. Assuming speed of light as $$3 	imes 10^{8} \mathrm{~m} / \mathrm{s}$$, the momentum of the object becomes equal to :

Accepted Answer

Assuming the small object as photon.
Momentum $$(p)=\frac{E}{C}$$
$$=\frac{20	imes10^{-3}	imes300	imes10^{-9}}{3	imes10^8}$$
$$=2	imes10^{-17}$$ kg m/s

Answer

$$1 	imes 10^{-17} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$$

Answer

$$0.5 	imes 10^{-17} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$$

Answer

$$3 	imes 10^{-17} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$$

Answer

$$2 	imes 10^{-17} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$$

Dual Nature of Matter and Radiation

A small object at rest, absorbs a light pulse of power $20 \mathrm{~mW} and duration 300 \mathrm{~ns}. Assuming speed of light as 3 \times 10^{8} \mathrm{~m} / \mathrm{s}$, the momentum of the object becomes equal to :

Choose the correct answer: