Answer: 15m/s
Explanation: <u>Average</u> <u>Velocity</u> is vector describing the total displacement of an object and the time taken to change its position. It is represented as:

At t₁ = 1.0s, displacement x₁ is:

x(1) = 28
At t₂ = 4.0s:

x(4) = 73
Then, average speed is

v = 15
The average velocity of a car between t₁ = 1s and t₂ = 4s is 15m/s
yeah it definitely 2 .:) :)
The "pitch" of a sound is the impression your brain forms
that corresponds to the frequency of the sound wave.
When the frequency is high, your brain says "high pitch".
When the frequency is low, your brain says "low pitch".
The answer is 1.52.
N = C (speed of light) / actual speed
n = index of refraction