Answer:
3 times louder
Explanation:
The Loudness in decibel Db L = 10㏒(I/I₀) where I = sound intensity level and I₀ = threshold of hearing = 10⁻¹² W/m².
Now, for Jessica, I₁ = sound intensity level of Jessica's music = 10⁻⁹
and I₂ = sound intensity level of Braylee's music = 10⁻³
So, substituting the variables into the equation, we have
L₁ = 10㏒(I₁/I₀)
L₁ = 10㏒(10⁻⁹/10⁻¹²)
L₁ = 10㏒(10³)
L₁ = 3 × 10㏒10
L₁ = 30㏒10
L₁ = 30 dB
Now, for Braylee, I₂ = sound intensity level of Braylee's music = 10⁻³
So, substituting the variables into the equation, we have
L₂ = 10㏒(I₁/I₀)
L₂ = 10㏒(10⁻³/10⁻¹²)
L₂ = 10㏒(10⁹)
L₂ = 9 × 10㏒10
L₂ =90㏒10
L₂ = 90 dB
So, the number of times Braylee's music is louder than Jessica's music is L₂/L₁ = 90 dB/30 dB = 3
So, Braylee's music is 3 times louder than Jessica's music
Answer:
Mass, m = 26.54kg
Explanation:
Net force can be defined as the vector sum of all the forces acting on a body or an object i.e the sum of all forces acting simultaneously on a body or an object.
Mathematically, net force is given by the formula;
Where;
- Fapp is the applied force
- Fg is the force due to gravitation
<u>Given the following data;</u>
Net force, Fnet = 345
Acceleration, a = 3.2m/s²
<u>To find mass;</u>
Fnet = Fapp + Fg
Fnet = ma + mg
Fnet = m(a+g)
m = Fnet/(a+g)
We know that acceleration due to gravity, g = 9.8m/s²
Substituting into the equation, we have;
m = 345/(3.2 + 9.8)
m = 345/13
Mass, m = 26.54kg
Answer:
the length of the wire is 134.62 m.
Explanation:
Given;
resistivity of the copper wire, ρ = 2.6 x 10⁻⁸ Ωm
cross-sectional area of the wire, A = 35 x 10⁻⁴ cm² = ( 35 x 10⁻⁴) x 10⁻⁴ m²
resistance of the wire, R = 10Ω
The length of the wire is calculated as follows;
Therefore, the length of the wire is 134.62 m.
Answer:
The lowest mass that an object can have to be considered a star is 0.08 solar masses.
Explanation:
A star is get when it reaches the necessary temperature in its core to nuclear reaction began.
A Nuclear reaction is the fusion of lighter elements into heavier elements.
In stars there is an equilibrium between two forces, the force of gravity in the inward direction due to its own mass and the radiation pressure in the upward direction as a consequence of the nuclear reaction in its core, which is known as hydrostatic equilibrium.
Therefore, the mass of the star must be enough to the force of gravity act in the inward direction, which leads to the increase in pressure, density and of course temperature in the core, allowing the nuclear reaction to begin.
Hence, the lowest mass that an object can have to be consider a star is 0.08 solar masses.
