Answer:
Explanation:
Given
Distance between two loud speakers 
Distance of person from one speaker 
Distance of person from second speaker 
Path difference between the waves is given by

for destructive interference m=0 I.e.




frequency is given by

where 

For next frequency which will cause destructive interference is
i.e.
and 


frequency corresponding to this is

for 


Frequency corresponding to this wavelength

I love science! if you need any more help let me know i cant guarantee i can help but i will try!
The correct answer is "Some substances must be dissolved in water before they can be used".
Answer:
Yeah it's right there from the one next to the exclamation point
Answer:
Positive velocity and negative acceleration
Explanation:
An object moving in the positive direction has a positive velocity.
An object that's slowing down while moving in the positive direction has a negative acceleration.
Explanation:
It is known that relation between force and acceleration is as follows.
F =
I is given that, mass is 1090 kg and acceleration is 21 m/s. Therefore, we will calculate force as follows.
F =
=
= 1430.625 N
Also, it is known that
= 7.70 degrees
Thus, we can conclude that the maximum steepness for the car to still be able to accelerate is 7.70 degrees.