The value of the underlined 8 is, hundred billion's. Hope this helped!
potential, kinetic, elastc energies
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
Scobie will take 10 days to drive around Earth's equator.
To calculate the time that takes Scobie to drive around Earth's equator we need to find the distance, which is given by the equation of a circumference:

<em>Where:</em>
r: is the Earth's radius = 6371 km
Then, the distance is:

Now, if we divide the above distance by the speed of the car we can find the time:

Therefore, Scobie will take 10 days to drive around Earth's equator.
To learn more about distance and time here: brainly.com/question/14236800?referrer=searchResults
I hope it helps you!
Gravitational I think would be the answer, Hope this helps!