Physics · 2020
JEE Main · 5 September 2020, Shift 2 · Q9
A driver in a car, approaching a vertical wall notices that the frequency of his car horn, has changed from 440 Hz to 480 Hz, when it gets reflected…
A driver in a car, approaching a vertical wall notices that the frequency of his car horn, has changed from $\displaystyle 440$ Hz to $\displaystyle 480$ Hz , when it gets reflected from the wall. If the speed of sound in air is $\displaystyle 345 \mathrm{~m} / \mathrm{s}$, then the speed of the car is :
Official answer
(1)
$\displaystyle 54$ km/hr
More from Waves
- Two loudspeakers ( L_1 and L_2 ) are placed with a separation of 10 m, as shown in figure. Both speakers are fed with an audio input signal of same…2026
- A travelling wave is described by the equation y(x, t)=[0.05 sin (8 x-4 t)] m The velocity of the wave is: [all the quantities are in SI unit]2023
- The equation of a wave travelling on a string is y= sin [20 π x+10 π t], where x and t are distance and time in SI units. The minimum distance…2025
- A tuning fork is vibrating at 250 Hz. The length of the shortest closed organ pipe that will resonate with the tuning fork will be \ \ \ \ cm. (Take…2021
- In an experiment with sonometer when a mass of 180 g is attached to the string, it vibrates with fundamental frequency of 30 Hz. When a mass m is…2023
- A source and a detector move away from each other in absence of wind with a speed of 20 m/s with respect to the ground. If the detector detects a…2021
- Two waves are simultaneously passing through a string and their equations are: y_1=A_1 sin k(x-vt), y_2=A_2 sin k(x-vt+x_0). Given amplitudes A_1=12…2021
- A student is performing the experiment of resonance column. The diameter of the column tube is 6 cm. The frequency of the tuning fork is 504 Hz.…2021
JEE Main 2020 Physics question, with the answer from NTA’s final answer key. Where our answers come from.