Answer:
1200KJ
Explanation:
The heat dissipated in the rotor while coming down from its running speed to zero, is equal to three times its running kinetic energy.
P (rotor-loss) = 3 x K.E
P = 3 x 300 = 900 KJ
After coming to zero, the motor again goes back to running speed of 1175 rpm but in opposite direction. The KE in this case would be;
KE = 300 KJ
Since it is in opposite direction, it will also add up to rotor loss
P ( rotor loss ) = 900 + 300 = 1200 KJ
Answer:
Explanation:
For pressure gage we can determine this by saying:
The closed tank with oil and air has a pressure of P₁ and the pressure of oil at a certain height in the U-tube on mercury is p₁gh₁. The pressure of mercury on the air in pressure gauge is p₂gh₂. The pressure of the gage is P₂.
We want to work out P₁-P₂: Heights aren't given so we can solve it in terms of height: assuming h₁=h₂=h
Answer:
15.8
0.0944
Explanation:
L = 1.5
B = 1.0
Speed of water = 15cm
Temperature = 20⁰C
At 20⁰C
Specific weight = 9790
Kinematic viscosity v = 1.00x10^-4m²/s
Dynamic viscosity u = 1.00x10^-3
Density p = 998kg/m²
Reynolds number
= 0.15x1.5/1.00x10^-4
= 225000
S = 5
5x1.5/225000^1/2
= 0.0158
= 15.8mm
Resistance on one side of plate
F = 0.664x1x1.0x10^-3x0.15x225000^1/2
= 0.04724N
Total resistance
= 2N
= 2x0.04724
= 0.0944N
