<u>Answer :</u>
(a) d = 0.25 m
(b) d = 0.5 m
<u>Explanation :</u>
It is given that,
Frequency of sound waves, f = 686 Hz
Speed of sound wave at 
is, v = 343 m/s
(1) Perfectly destructive interference occurs when the path difference is half integral multiple of wavelength i.e.
........(1)
Velocity of sound wave is given by :
Hence, when the speakers are in phase the smallest distance between the speakers for which the interference of the sound waves is perfectly destructive is 0.25 m.
(2) For constructive interference, the path difference is integral multiple of wavelengths i.e.
( n = integers )
Let n = 1
So, 
Hence, the smallest distance between the speakers for which the interference of the sound waves is maximum constructive is 0.5 m.
C i would think
it sounds best
Answer:
The correct answer is A
Explanation:
The question requires as well the attached image, so please see that below.
Coulomb's Law.
The electrical force can be understood by remembering Coulomb's Law, that describes the electrostatic force between two charged particles. If the particles have charges 
and 
, are separated by a distance r and are at rest relative to each other, then its electrostatic force magnitude on particle 1 due particle 2 is given by:
Thus if we decrease the distance by half we have
So we get
Replacing we get
We can then multiply both numerator and denominator by 4 to get
So we have
Thus if we decrease the distance by half we get four times the force.
Then we can replace the second condition
So we get
which give us
Thus doubling one of the charges doubles the force.
So the answer is A.
50km / 2.5 = 20 km per hour
Answer:
B.) if statistical results are significant
Explanation:
If a scientist accepts the null hypothesis, then there is enough evidence to reject the null hypothesis.
This means that the p-value is less than the significance level.
When the scientist accepts the alternative hypothesis, it means the statistical results are significant.
The correct answer is B.
