Answer:
Explanation:
Assuming uniform spread of sound with no significant reflections or absorption. We know that sound intensity varies 
where r is the distance
Since intensity is given then when at 3 m
Since we have the constant then at 4m
Intensity, 
Answer:
hi there!!
Explanation:
Nickel 149 pm
Cobalt 152 pm
Calcium 194 pm
Potassium 243 pm
So Potassium is the correct answer
Answer:
The rougher a surface is, the more friction it can create.
Explanation:
The rougher a surface is, the more "holes" are on the edge which means things can get caught on in because multiple holes can catch each other.
Answer:
24
Explanation:
If it took 3 hours to clean 6 houses than you can figure that is 2 houses per hours. so if there are 12 hours and 2 houses an hour, you multiply 12x2 and get 24. Another way to do it is to use proportions (aka two fractions that equal eachother):
3 hours 12 hours
---------------- = ---------------
6 houses number of houses
To calculate this, we can think about how we go from 3 to 12. Well, 3x4 is 12, so we got to 12 by doing multiplying by 4. So we can multiply 6 by 4 and you get 24.
<u><em>Hope it helps! have a great day :)</em></u>
