
Answer:
Explanation:
Let the velocity of car be v . We shall apply doppler's effect . Here the car is running towards the observer .
f = fâ‚€ x( [tex]\frac{V}{V-v}[/tex] )
Here f is apparent frequency fâ‚€ is true frequency , V is velocity of sound and v is velocity of source .
Putting the values
860 = 800 x  340 / (340 - v )
1.075 = 340 / Â (340 - v )
365.5 - 1.075 v = 340
25.5 = 1.075 v
v = 23.72 m /s