This would be an illustration of Newton's first law of motion. Law of inertia, an object moving at constant velocity will keep moving at constant velocity until a force is acted upon it. Inertia is the tendency of an object to keep moving in a particular direction resisting to change, unless a force acts upon the object.
The answers is 30 miles per hour, the driver is speeding the car up, section-H, 12 minutes, section-D, and 65 miles per hour.
The answer to your question is A
Answer:
64.945 miles per hour
Explanation:
Since the frequency of sound heard is higher than actual frequency, the ambulance is moving towards you!
The frequency of sound waves as heard from a distance for a sound wave coming towards one at v₀ m/s and whose real frequency is f₀ is given by
+f = f₀/[1 - (v₀/v)]
+f = frequency of sound as heard from the distance away = 8.61 KHz
f₀ = real frequency of sound = 7.87 KHz
v₀ = velocity at which the sound source is moving towards the reference point = ?
v = velocity of sound waves = 343 m/s
8.61 = 7.87/(1 - (v₀/v))
1 - (v₀/343) = 0.9141
v₀/343 = 1 - 0.9141 = 0.0859
v₀ = 343 × 0.0859 = 29.48 m/s = 64.945 miles per hour
