Answer:
Explanation:
Suppose the distance between the two cities is D and the velocity in calm weather is V . The total time taken in two way travel is given by
Total distance / velocity
= 2 D / V
Suppose velocity of wind is v . Then in one way the velocity of airplane will become V + v and in the return trip its velocity will be V - v
Total time taken
= 
= 
= 
= 
= The denominator contains a factor
which is less than one so time calculated will be more than
2D / V
Hence in the second case time taken will be more .
efficiency= [useful energy transferred ÷ total energy supply]×100%
So, [5500÷10000]×100%=0.55×100
=55%
Answer:
-40 kJ
80 kJ
Explanation:
Work is equal to the area under the pressure vs volume graph.
W = ∫ᵥ₁ᵛ² P dV
2.27) Pressure and volume are linearly related. When we graph P vs V, the area under the line is a trapezoid. So the work is:
W = ½ (P₁ + P₂) (V₂ − V₁)
W = ½ (100 kPa + 300 kPa) (0.1 m³ − 0.3 m³)
W = -40 kJ
2.29) Pressure and volume are inversely proportional:
pV = k
The initial pressure and volume are 500 kPa and 0.1 m³. So the constant is:
(500) (0.1) = k
k = 50
The final pressure is 100 kPa. So the final volume is:
(100) V = 50
V = 0.5
The work is therefore:
W = ∫ᵥ₁ᵛ² P dV
W = ∫₀₁⁰⁵ (50/V) dV
W = 50 ln(V) |₀₁⁰⁵
W = 50 (ln 0.5 − ln 0.1)
W ≈ 80 kJ
Explanation:
Below is an attachment containing the solution.
Answer:
The weight of heart of a human is 0.93 lbs.
Explanation:
Given that,
Approximately weight of heart is 0.5 % of the total body weight.
Weight of human = 185 lbs
Let the the weight of total body is w and weight of heart is 
.
We need to calculate the weight of heart of a human
Using given data
Where, h = weight of heart
w = weight of human
Hence, The weight of heart of a human is 0.93 lbs.
