Answer:
The answer is A. on edgen.
Explanation:
A. adding in the boxes an arrow that points from Qh to Qc
Thermal conductions
K= QL/ART
Aluminium T₁ = 10 + 273.15
T₂ = 283.15k
205 = 2.0 × 0.30/4× 10⁻⁴ × (T₂ - 283.15)
Copper
385 = Q × 0.70/4×10⁻⁴ ×(433.15 - T₂)
Where T₃ = 160 + 273.15
T₃ = 433.15K
From 2 to 3
205/385 = 0.30/0.70 × 433.15 - T₂/T₂ - 283.15
= 0.53T₂ -150.06 = 181.92 - 0.42 T₂
→ 0.95T₂ = 331.98 ⇒ T₂ = ₂349.45k
T₂ = 76.3°c
=77°c.
As the number of significant figures increases, the more accurate or precise the measurement is.
<h3>What is significant figure?</h3>
The term significant figures refers to the number of important single digits in the coefficient of an expression in scientific notation.
Significant figures are the digits in a value that are known with some degree of confidence.
The effect of reporting more or fewer figures or digits than are significant;
As the number of significant figures increases, the more accurate or precise the measurement is.
As precision of a measurement increases, so does the number of significant figures.
Learn more about significant figures here: brainly.com/question/24491627
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Answer:
v = 29.4 m / s
Explanation:
For this exercise we can use the conservation of mechanical energy
Lowest starting point.
Em₀ = K = ½ m v²
final point. Higher
= U = m g h
Let's use trigonometry to lock her up
cos 60 = y / L
y = L cos 60
Height is the initial length minus the length at the maximum angle
h = L - L cos 60
h = L (1- cos 60)
energy is conserved
Em₀ = Em_{f}
½ m v² = mgL (1 - cos 60)
v = 2g L (1- cos 60)
let's calculate
v² = 2 9.8 3.0 (1- cos 60)
v = 29.4 m / s
