Ok, let me see if I can help
Sound is caused by vibrations. These can pass through a solid, liquid, and gas. But not through vacuum because there are no particles
The force equation can easily prove this. F=ma. This states that the force on an object is equal to mass times acceleration. If the mass stays the same and the velocity of the cars increases than that means there is a larger force. This is because in both cases the cars are stopping in almost an instant and the times of the crashes are theoretically identical. Acceleration is the change in velocity over time. If the velocity is higher with the same amount of time than that means there is a higher acceleration. If you plug a higher acceleration into the force equation then you wind up with a higher force and in turn a more damaging collision.
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The evidence that the universe is expanding comes with something called the red shift<span> of light. Light travels to Earth from other galaxies. As the light from that galaxy gets closer to Earth, the distance between Earth and the galaxy increases, which causes the wavelength of that light to get longer.</span>
Answer:
<em>v = 381 m/s</em>
Explanation:
<u>Linear Speed</u>
The linear speed of the bullet is calculated by the formula:

Where:
x = Distance traveled
t = Time needed to travel x
We are given the distance the bullet travels x=61 cm = 0.61 m. We need to determine the time the bullet took to make the holes between the two disks.
The formula for the angular speed of a rotating object is:

Where θ is the angular displacement and t is the time. Solving for t:

The angular displacement is θ=14°. Converting to radians:

The angular speed is w=1436 rev/min. Converting to rad/s:

Thus the time is:

t = 0.0016 s
Thus the speed of the bullet is:

v = 381 m/s