Explanation:
Given that,
Distance 1, r = 100 m
Intensity, 
If distance 2, r' = 25 m
We need to find the intensity and the intensity level at 25 meters. Intensity and a distance r is given by :
.........(1)
Let I' is the intensity at r'. So,
............(2)
From equation (1) and (2) :



Intensity level is given by :
, 

dB = 32.96 dB
Hence, this is the required solution.
Explanation:
Q = mc∆T
= (0.34 kg)(94 J/kg-°C)(25°C)
= 799 J
Answer:
Average speed is 60 km/hour
Explanation:
When we need to calculate average speed, we use this equation:

Where:
position at the beginning
at the end


Then: 

Finally V = 60 km/hour
We have here what is known as parallel combination of resistors.
Using the relation:

And then we can turn take the inverse to get the effective resistance.
Where r is the magnitude of the resistance offered by each resistor.
In this case we have,
(every term has an mho in the end)

To ger effective resistance take the inverse:
we get,

The potential difference is of 9V.
So the current flowing using ohm's law,
V = IR
will be, 0.0139 Amperes.