Question

Q. A car approaches a hill with a constant speed. When it is at a distance of 0.96 km, it blows horn whose Eco is heard by the driver 3 second later. If the speed of the sound in air is 300 m/s. Then calculate the speed of the car.​

Bad evening but why??​?

Answer 1

Answer: Distance travelled by engine = v x 6sec =

x m

Distance travelled by sound =960+(960−x) =(1920−x)m ⇒

velocity of sound=300m/s

v = distance/time

300= (1920−x)6

1800=1920−x

x=1920−1800

x=120m

Speed of car = x/5

=120/6

=20m/s

Step-by-step explanation:

Answer 2

Answer:

Here, t = 6 s and speed of sound vs=300m/sNow, distance travelled by the car = v×6=xDistance travelled by sound, s=960+(960−x)=(1920−x)mSince, vs=stor 330=(1920−x)6or1800=1920−xx = 120 mSpeed of car, v=x6=1206=20m/s

hope it helps you zara.