Answer:
Surface tension is, the surface where the water meets the air, water molecules cling even more tightly to each other.
Answer:
A = B = C > D
Explanation:
Work done to stop the disc is given as
so we have
(a) –2 rad/s, 5 rad/s;
(b) 2 rad/s, 5 rad/s;
(c) –2 rad/s, –5 rad/s; and
(d) 2 rad/s, –5 rad/s.
So we have
so we have
A = B = C > D
Answer:
a) 5.22 m/s
b) 31.4 %
Explanation:
f = rotating speed = 15 rpm = 15/60 =0.25 rps
m = Mass flow rate of air = 42000 kg/s
v = Tip velocity = 250 km/h = 250/3.6 = 69.44 m/s
W = Work output = 180 kW
A = Swept area of wind turbine
r = Radius of wind turbine
η = Efficiency
∴ The average velocity of the air is 5.22 m/s
∴ Conversion efficiency of the turbine is 0.314 or 31.4 %
Answer:
The work required to cause this volume change is 2 x 10⁶ J
Explanation:
Given;
constant pressure of the gas, P = 100 kPa = 100,000 Pa
change in volume of the gas, ΔV = 20 m³
The work required to cause this volume change is calculated as;
W = PΔV
Substitute the given values and solve for the required work (W).
W = (100,000)(20)
W = 2 x 10⁶ J
Therefore, the work required to cause this volume change is 2 x 10⁶ J