The speed of sound in an ideal gas is given by the relationship v = γrtm√ , where r - the universal gas constant = 8.314 j/mol⋅k ; t - the absolute temperature; m - the molar mass of the gas in kg/mol ; and γ is a characteristic of the specific gas. for air, γ = 1.4. calculate the speed of sound in the air. assume that air is 20% oxygen and 80% nitrogen and the temperature of air is 293 k . express your answer to two significant figures and include the appropriate units.

part b

while camping, you record a thunderclap whose intensity is 10−2 w/m2 . the clap reaches you 3.0 s after a flash of lightning. assume that the thunder radiates spherically from its source. estimate the total acoustical power generated by the bolt of lightning. express your answer to two significant figures and include the appropriate units.

The particle in a two-dimensional well is a useful model for the motion of electrons around the indole ring (3), the conjugated cycle found in the side chain of tryptophan. we may regard indole as a rectangle with sides of length 280 pm and 450 pm, with 10 electrons in the conjugated p system. as in case study 9.1, we assume that in the ground state of the molecule each quantized level is occupied by two electrons. (a) calculate the energy of an electron in the highest occupied level. (b) calculate the frequency of radiation that can induce a transition between the highest occupied and lowest unoccupied levels. 9.27 electrons around the porphine ring (4), the conjugated macrocycle that forms the structural basis of the heme group and the chlorophylls. we may treat the group as a circular ring of radius 440 pm, with 20 electrons in the conjugated system moving along the perimeter of the ring. as in exercise 9.26, assume that in the ground state of the molecule quantized each level is occupied by two electrons. (a) calculate the energy and angular momentum of an electron in the highest occupied level. (b) calculate the frequency of radiation that can induce a transition between the highest occupied and lowest unoccupied levels.

Which of the following is not a transverse wave? a) soundb) lightc) radiod) all of thesee) none of these

14. a body is projected with velocity vi from a.at the same time another body is projectedvertically upwards from point b withvelocity v2 lies vertically below the highestpoint. both the bodies collide thenv2÷v1is