Question

# According to Newton's formula, the speed of sound in air at STP is:(Take the mass of $$1$$ mole of are is $$29 \times 10^{-3} \,\,kg)$$

A
250ms1
B
260ms1
C
270ms1
D
280ms1

Solution

## The correct option is D $$280 \,\, m \,\,s^{-1}$$$$1$$ mole of any gas occupies $$22.4$$ liters at STP.Therefore, the density of air at STP is$$\rho = \dfrac{\text{Mass of one mole of air}}{\text{Volume of one mole of air at STP}}$$$$= \dfrac{29 \times 10^{-3} \,\,kg}{22.4 \times 10^{-3} \,\,m^3} = 1.29 \,\,kg \,\,m^{-3}$$At STP, $$P = 1\,\,atm = 1.01 \times 10^5 \,\,N \,\,m^{-2}$$$$V =\sqrt{\left( \dfrac { P }{ \rho }\right)}=\sqrt { \dfrac {1.01 \times 10^5 \,\,N \,\,m^{-2} }{ 1.29 \times kg \,\,m^{-3} } } = 280 \,\,m \,\,s^{-1}$$Physics

Suggest Corrections

0

Similar questions
View More

People also searched for
View More