Answer:
The percentage change in resistance of the wire is 69%.
Explanation:
Resistance of a wire can be determined by,
R = (ρl) ÷ A
Where R is its resistance, l is the length of the wire, A its cross sectional area and ρ its resistivity.
When the wire is stretched, its length and area changes but its volume and resistivity remains constant.
= 1.3l, and =
So that;
= (ρ) ÷ = (ρ × 1.3l) ÷ ()
= (1.3lρ) ÷ ()
= × [(ρl) ÷ A]
= 1.69R (∵ R = (ρl) ÷ A)
= 1.69R
Where is the new resistance, is the new length, and is the new area after stretching the wire.
The change in resistance of the wire = - R
= 1.69R - 1R
= 0.69R
The percentage change in resistance = × 100
= 0.69 × 100
= 69%
The percentage change in resistance of the wire is 69%.
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
I think the correct answer from the choices listed above is the second option. An impact of a thermoelectric power plant on the environment would be it <span>uses a lot of water which will significantly decrease the supply and amount of water available for use. Hope this answers the question. Have a nice day. </span>
I believe it’s D) it will increase by 10x because when temperature increasing particles move faster causing things to expand like when you put a bottle of syrup in the microwave.
Answer:It started at 20°C, the bras and the iron must b cooled at -150°C.
Explanation:
The formular for linear expansion is given by:
L = Lo + Lo&◇T
Where L = linear dimensions)diameter) after temperature change.
Lo=Original linear dimension
&= Coefficient of thermal expansion for the material.
◇T=Change in temperature.
At some temperature,L(brass)=L(iron)
Lo + Lo&◇T = Lo + Lo&◇T
8.753cm + 8.753cm×(8.7×10^-6C^-1)×◇T=8.753cm+ 8.753cm ×(12.0×10^-6C^-1)×◇T
8.753+(1.636×10^-4)◇T= 8.753+(1.049×10^-4C^-1)◇T
5.87 × 10^-5◇T= 0.010
◇T= 0.010/(5.87×10^-5)
◇T= 170°C
◇T=T1-T2
T= (20 - 170)°C
T= -150°C