A petrol engine produces 20 hp using 35 kW of heat transfer from burning fuel. What is its thermal efficiency, and how much powe
1 answer:
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Answer:
Temperature at center of apples = 11.2⁰C
Temperature at surface of apples = 2.7⁰C
Amount of Heat transferred = 17.2kJ
Explanation:
The properties of apple are given as:
k = 0.418 W/m.°C
ρ = 840 kg/m³
Cр = 3.81 kJ/kg.°C
α = 1.3*10 ⁻⁷ m²/s
h = 8 W/m².°C
d = 0.09m
r = 0.045m
t = 1 hour = 3600s
<h2>Solution</h2>Biot number is given as:
The constants λ₁ and A₁ corresponding to Biot number (from the table) are:
λ₁ = 1.476
A₁ = 1.239
Fourier Number is:
As Fourier Number > 0.2 , one term approximates solutions are applicable
The temperature at the center of apples, The temperature at surface of apples and Amount of heat transfer is found in the ATTACHMENT.
Answer:
Option (d) 2 min/veh
Explanation:
Data provided in the question:
Average time required = 60 seconds
Therefore,
The maximum capacity that can be accommodated on the system, μ = 60 veh/hr
Average Arrival rate, λ = 30 vehicles per hour
Now,
The average time spent by the vehicle is given as
⇒
thus,
on substituting the respective values, we get
Average time spent by the vehicle =
or
Average time spent by the vehicle =
or
Average time spent by the vehicle =
or
Average time spent by the vehicle = hr/veh
or
Average time spent by the vehicle = min/veh
[ 1 hour = 60 minutes]
thus,
Average time spent by the vehicle = 2 min/veh
Hence,
Option (d) 2 min/veh
Answer:
0.867
Explanation:
The driver population factor ()can be estimated using the equation below:
The value of the heavy vehicle factor () is determined below:
The values of the = 2 and
= 3 are gotten from the tables for the RVs, trucks and buses upgrades for passenger-car equivalents. Therefore:
= 1/[1+0.08(2-1)+0.06(3-1)] = 1/[1+0.08+0.12] = 1/1.2 = 0.833
Furthermore, the vp is taken as 2250 pc/(h*In) from the table of LOS criteria for lane freeway using the 15 minutes flow rate. Therefore:
= 3900/[0.8*3*0.833*2250] = 3900/4498.2 = 0.867