B.adding carpet and fabric wall covering to absorb sound
Answer:
800 meters per hour
Explanation:
800 meters per hour is the average speed of an airplane that travels from New York to Los Angeles, a total distance of 4800 km, in 6.0 hours.
The statement shows a case of rotational motion, in which the disc <em>decelerates</em> at <em>constant</em> rate.
i) The angular acceleration of the disc (
), in revolutions per square second, is found by the following kinematic formula:
(1)
Where:
- Initial angular speed, in revolutions per second.
- Final angular speed, in revolutions per second. 
- Time, in seconds.
If we know that 
, 
y 
, then the angular acceleration of the disc is:
The angular acceleration of the disc is 
radians per square second.
ii) The number of rotations that the disk makes before it stops (
), in revolutions, is determined by the following formula:
(2)
If we know that , y , then the number of rotations done by the disc is:
The disc makes 3.125 revolutions before it stops.
We kindly invite to check this question on rotational motion: brainly.com/question/23933120
If the spaceship's Physicist happens to be hanging out of one side
of the ship, and he measures the speed of the photons as they pass
him and leave the ship, he'll see them passing him at 'c' ... the speed
of light.
When those photons pass somebody who happens to be in their
path, and he decides to measure their speed, he'll see them move
past him at 'c' ... the speed of light.
It doesn't matter whether the observer who measures them is
moving, or at what speed.
And it doesn't matter what source the photons come from, or
whether the source is moving, or at what speed.
And it doesn't matter what the photons' wavelength/frequency is ...
anything from radio to gamma rays.
The photons pass everybody at 'c' ... the speed of light.
Yes, I hear you. That can't be true. It's crazy.
Maybe it's crazy, but it's true.
