Answer:
1.37 rad/s
Explanation:
Given:
Total length of the tape is,
m
Total time of run is,
hours
We know, 1 hour = 3600 s
So, 2.1 hours = 2.1 × 3600 = 7560 s
So, total time of run is,
s
Inner radius is, 
Outer radius is, 
Now, linear speed of the tape is, 
Let the same angular speed be
.
Now, average radius of the reel is given as the sum of the two radii divided by 2.
So, average radius is, 
Now, common angular speed is given as the ratio of linear speed and average radius of the tape. So,

Therefore, the common angular speed of the reels is 1.37 rad/s.
Answer: Yes
Air serves as a propagation medium.
Explanation:
Propagation of sound wave require a medium for transmission. Sound is produced by vibrating objects, The matter or substance through which sound is transmitted is called a medium. It can be solid, liquid or gas. Therefore to propagate sounds (human voice) from one end of a lecture hall to the other we need a propagation medium which is air. Air serves as a propagation medium.
1). The equation is: (speed) = (frequency) x (wavelength)
Speed = (256 Hz) x (1.3 m) = 332.8 meters per second
2). If the instrument is played louder, the amplitude of the waves increases.
On the oscilloscope, they would appear larger from top to bottom, but the
horizontal size of each wave doesn't change.
If the instrument is played at a higher pitch, then the waves become shorter,
because 'pitch' is directly related to the frequency of the waves, and higher
pitch means higher frequency and more waves in any period of time.
If the instrument plays louder and at higher pitch, the waves on the scope
become taller and there are more of them across the screen.
3). The equation is: Frequency = (speed) / (wavelength)
(Notice that this is exactly the same as the equation up above in question #1,
only with each side of that one divided by 'wavelength'.)
Frequency = 300,000,000 meters per second / 1,500 meters = 200,000 per second.
That's ' 200 k Hz ' .
Note:
I didn't think anybody broadcasts at 200 kHz, so I looked up BBC Radio 4
on-line, and I was surprised. They broadcast on several different frequencies,
and one of them is 198 kHz !
4 atoms
Explanation:
On the product side, we expect to find 4 atoms of the product.
An atom is the smallest indivisible particle that takes part in a chemical reaction.
An element is a distinct substance that cannot be split-up into simpler substances. Such substances consist of only one kind of atom.
In this reaction we have:
2 elements: Mg O
on the reactant side:
We have two moles of Mg: 2 atoms of Mg
1 mole of oxygen gas: 2 atoms of O
total atoms: 4 atoms
According to the law of conservation of matter "in a chemical reaction, matter is neither created nor destroyed".
We expect to find 4 atoms of products which is MgO on the product side.
2Mg + O₂ → 2MgO + heat
Learn more:
Conservation of matter brainly.com/question/2190120
#learnwithBrainly
Answer:
your right answer is true
hope it helps you