A train, standing at the outer signal of a railway station blows a whistle of frequency $400 \mathrm{~Hz}$ in still air. (i) What is the frequency of the whistle for a platform observer when the train (a) approaches the platform with a speed of $10 \mathrm{~m} \mathrm{~s}^{-1}$, (b) recedes from the platform with a speed of $10 \mathrm{~m} \mathrm{~s}^{-1}$ ? (ii) What is the speed of sound in each case? The speed of sound in still air can be taken as $\mathbf{3 4 0} \mathrm{m} \mathrm{s}^{-1}$.

Home » A train, standing at the outer signal of a railway station blows a whistle of frequency in still air. (i) What is the frequency of the whistle for a platform observer when the train (a) approaches the platform with a speed of , (b) recedes from the platform with a speed of ? (ii) What is the speed of sound in each case? The speed of sound in still air can be taken as .

A train, standing at the outer signal of a railway station blows a whistle of frequency $400 \mathrm{~Hz}$ in still air. (i) What is the frequency of the whistle for a platform observer when the train (a) approaches the platform with a speed of $10 \mathrm{~m} \mathrm{~s}^{-1}$ , (b) recedes from the platform with a speed of $10 \mathrm{~m} \mathrm{~s}^{-1}$ ? (ii) What is the speed of sound in each case? The speed of sound in still air can be taken as $\mathbf{3 4 0} \mathrm{m} \mathrm{s}^{-1}$ .

CBSE | Class 11 | NCERT | Physics | Waves

A train, standing at the outer signal of a railway station blows a whistle of frequency $400 \mathrm{~Hz}$ in still air. (i) What is the frequency of the whistle for a platform observer when the train (a) approaches the platform with a speed of $10 \mathrm{~m} \mathrm{~s}^{-1}$ , (b) recedes from the platform with a speed of $10 \mathrm{~m} \mathrm{~s}^{-1}$ ? (ii) What is the speed of sound in each case? The speed of sound in still air can be taken as $\mathbf{3 4 0} \mathrm{m} \mathrm{s}^{-1}$ .

Frequency of the whistle is given as $=400 \mathrm{~Hz}$