Answer:
Efficiency of the machine = 75%
Explanation:
Given:
Input work = 8,000 J
Output work = 6,000 J
Find:
Efficiency of the machine
Computation:
Efficiency of the machine = [Output work / Input work]100
Efficiency of the machine = [6,000 / 8,000]100
Efficiency of the machine = 75%
The result is although the wire's resistivity doesn't change, its resistance does.
Considering the formula for a material's resistance:
R=pL/A
R is directly proportional to L and inversely proportional to A, as can be seen. Be aware that "rho" is a material-specific and intensive attribute (meaning this value will not change if the material is only physically altered). Remember that A = This implies that the relationship between R and the square of r is inverse. When the wire is stretched, the impacts on length are less noticeable than the effects on r. Therefore the wire's resistance increases, but its resistivity stays the same.
Learn more about resistance here:
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Answer:
β = 114 db
Explanation:
The intensity of sound in decibles is
β = 10 log 
in most cases Io is the hearing threshold 1 10-12 W / cm²
let's calculate the intensity of each instrument
I / I₀ = 10 (β / 10)
I = I₀ 10 (β / 10)
trumpet
I1 = 1 10⁻¹² 10 (94/10)
I1 = 2.51 10⁻³ / cm²
Thrombus
I2 = 1 10⁻¹² 10 (107/10)
I2 = 5.01 10-2 W / cm²
low
I3 =1 1-12 (113/10) W/cm²
I3 = 1,995 10-1 W / cm²
when we place the three instruments together their sounds reinforce
I_total = I₁ + I₂ + I₃
I_ttoal = 2.51 10-3 + 5.01 10-2 + 1.995 10-1
I_total = 0.00251 + 0.0501 + 0.1995
I_total = 0.25211 W / cm²
let's bring this amount to the SI system
β = 10 log (0.25211 / 1 10⁻¹²)
β = 114 db
In circular motion we know that there is two type of acceleration that Cheryl experience
1. Tangential acceleration
2. Centripetal acceleration
here given that

for centripetal acceleration we know that


now we know that both centripetal acceleration and tangential acceleration is perpendicular to each other
so total acceleration is vector sum of both and given as

so total acceleration is 8.54 m/s^2