Answer:
Explanation:
In the decibel scale , intensity of sound changes logarithmically as follows
Value in decibel scale , the value of I₀ = 10⁻¹² W /m².
Putting the values
W/m²
Similarly for 54 dB sound intensity can be given as follows
I = 10⁻¹² x
W / m²
For intensity of sound the relation is as follows
I = 2π²υ²A²ρc where υ is frequency , A is amplitude , ρ is density of air and c is velocity of sound .
Putting the given values for 71 dB
= 2π² x 504²xA²x 1.21 x 346
A² = 60.03 x 10⁻¹⁶
A = 7.74 x 10⁻⁸ m
For 54 dB sound
= 2π² x 504²xA²x 1.21 x 346
A² = 1.1978 x 10⁻¹⁶
A = 1.1 x 10⁻⁸ m
Answer:
The answer is 0.8 m
Explanation:
According the attached diagram, if we take the momentum in the point 0:
Where
mD = mass of Diane = 64.2 kg
mJ = mass of Jack = 93.6 kg
Replacing:
In this case, volume of the can remains constant. The relationship between pressure and temperature at constant volume is given by:
P/T = Constant
Then
Where
P1 = 40 psi
P2 = ?
T1 = 60°F ≈ 289 K
T2 = 90°F ≈ 305 K (note, 363 K is not right)
Substituting;
Answer:
18.24 seconds
Explanation:
First you convert the km/h to m/s, 70km/h=(175/9)m/s,85km/h=(425/18)m/s.
You know it took 10 seconds for the police to reach 85 km/h. Calculate the distance that the car is ahead of the police (175/9)*10=1750/9m. Then by divide 1750/9 with 425/18, you will get the value 8.24. Add the 10 seconds with the 8.24 you will get 18.24 sec which is the total time.