The value of gravitational acceleration of a body on earth is 9.8m/s^2. The gravitational potential energy for a 1.00 kilogram o
1 answer:
Answer:
The object is 1.2755 meters above the ground
Explanation:
Recall the formula for gravitational potential energy for an object of mass "m" at a height "h" above the ground:
In this case, since we are given the mass of the object and the object's potential energy, we can estimate the only unknown (height "h") from the formula shown above. Also since all units are given in the SI system, the result for the object's height will result in meters:
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Answer:
W = 5701 KW
Explanation:
From the question let inlet be labelled as point 1 and exit as point 2, for the fluid steam, we can get the following;
Inlet (1): P1 = 40 bar ; T1 = 500°C and V1 = 200 m/s
Exit(2) : At saturated vapour; P2 = 0.8 bar and V2 = 150 m/s
Volumetric flow rate = 15 m^(3)/s
Now, to solve this question, we assume constant average values, steeady flow and adiabatic flow.
Specific volume for steam at P2 = 0.8 bar in the saturated vapour state can be gotten from saturated steam tables(find a sample of the table attached to this answer).
So from the table,
v2 = 2.087 m^(3)/kg
Now, mass flow rate (m) = (AV) /v
Where AV is the volumetric flow rate.
Thus, the mass flow rate at exit could be calculated as;
m = 15/(2.087) = 7.17 kg/s
We also know energy equation could be defined as;
Q-W = m[(h1 - h2) + {(V2(^2) - (V1(^2)} /2)} + g(Z2 - Z1)]
Since the flow is adiabatic, potential energy can be taken to be zero. Therefore, we get;
-W = m[(h2 - h1) + {(V2(^2) - (V1(^2)} /2)}
From, table 2, i attached , at P1 = 40 bar and T1 = 500°C; specific enthalpy was calculated to be h1 = 3445.3 KJ/Kg
Likewise, at P2 = 0.8 bar; from the table, we get specific enthalpy as;
h2 = 2665.8 KJ/Kg
So we now calculate power developed;
W = - 7.17 [(2665.8 - 3445.3) + {(150^(2) - 200^(2))/2000 = 5701KW
Since the sign is not negative but positive, it means that the power is developed from the system.
