Answer:
81.29 m/s
Explanation:
Given:
60°C = 333 K is cp = 1.007 kJ/kg·K.
at air inlet:
Pressure = 100 kPa
Temperature = 30°C
Velocity = 357 m/s
at air outlet:
Pressure = 200kPa
Temperature = 90°C
We can define the energy balance as:
- = Δ = 0
therefore, =
m + m =m + (taking m common and cancelling it)
4 + = +
The velocity at the exit of a diffuser:
= [ + 2 ( - )
= [ + 2 x 1000 x 1.007 x (30-90)
= 81.29 m/s
therefore, the velocity at the exit of a diffuser is 81.29 m/s
Answer:
Exit velocity = 498.3m/s
Explanation:
The energy balance for the system is given by:
Ein - Eout = ◇Esystem
Ein = Eout
Therefore
m' (h1 + V1^2/2) = m' (h2 + V2^2/2)
h1 + V1^2/2 = h2 + V2^2/2
The exit velocity will be:
V2 = [V1^2 + 2(h1 - h2)^0.5 = [V1^2 + 2(cp(T1 - T2)]^0.5
But cp = 1.007kJ/kg
V2 = [(357)^2 + 2(1.007)(90-30)(1000m^2/s^2)]^0.5
V2 = [127449 + 120840]^0.5
V2 = [248289]^0.5
V2 = 498.3m/s
890 m/s 850 m/s 790 m/s 895 m/s 870 m/s
Car A
Car B
Car C
Car D
Car E
The mass of each car is the same so car D will take the longest time to come to a full stop. Hence, option D is correct.
In mechanics, acceleration is a unit used to describe how quickly the velocity of an object varies in relation to time. The direction of the net force acting on an object determines its acceleration.
Since acceleration has both a magnitude and a direction, it is a vector quantity. Velocity is another vector quantity. Acceleration is defined as the change in velocity vector over a time interval divided by the time interval.
According to the question, we want to determine which automobile will take the longest to fully stop because we know that each one has the same mass and the same velocity. Here, we can assume that all the vehicles slow down uniformly, thus the vehicle traveling at the maximum speed will take the longest to come to a complete stop.
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Answer: Car D.
Explanation:
We know that each car has the same mass, and knowing the velocity of each car, we want to know which car will require the longest time to come to a full stop. Here we may assume that all the cars decelerate at the same rate, so the car with the highest speed is the car that will take the longest income to a full stop.
The answer is car D, which velocity is 895 m/s.