Jane waits on a railroad platform while two trains approach from the same direction at equal speeds of 7.10 m/s. both trains are blowing their whistles (which have the same frequency), and one train is some distance behind the other. after the first train passes jane but before the second train passes her, she hears beats of frequency 6.50 hz. what is the frequency of the train whistles


the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.

Ibelieve your answer is b.hope this : )

156.96691 Hz


f' = Actual frequency

v = Velocity of sound in air = 343 m/s

v_r = Relative velocity of train = 7.1 m/s

\Delta f = Beat frequency = 6.5 Hz

Receding frequency

f_1=f'\dfrac{v}{v-v_r}\\\Rightarrow f_1=f'\dfrac{343}{343-7.1}\\\Rightarrow f_1=f'1.02113

Approaching frequency

f_2=f'\dfrac{v}{v+v_r}\\\Rightarrow f_2=f'\dfrac{343}{343+7.1}\\\Rightarrow f_2=f'0.97972

Beat frequency is given by

\Delta f=f_1-f_2\\\Rightarrow 6.5=f'1.02113-f'0.97972\\\Rightarrow 6.5=f'0.04141\\\Rightarrow f'=\dfrac{6.5}{0.04141}\\\Rightarrow f'=156.96691\ Hz

Actual frequency of the train whistle is 156.96691 Hz

Do you know the answer?

Other questions on the subject: Physics

Physics, 22.06.2019, Nadi4753
1. 50 m2. The time it would take Maria to reach planet x according to Samir is 0 yearsExplanation:1. Here we have;Where:v = Velocity of Maria's spaceship relative to Samir's spaces...Read More
3 more answers
Physics, 22.06.2019, xxaurorabluexx
The law of conservation of momentum will be the same no matter where you apply it.the equation will be  77.4 + m (mass of canister) *3.6...Read More
1 more answers
as we know our atmosphere or air have different levels. every level has other gasses, and every gas has another permeability. when the light comes from lower permeability to higher...Read More
1 more answers