Which graph showing constant acceleration correctly places the independent and dependent variables?

In-s [12.5K]

Answer:

Speed is a scalar quantity it is the rate of change in the distance travelled by an object, while velocity is a vector quantity it is the speed of an object in a particular direction.

4 0

3 years ago

A wind turbine is rotating at 15 rpm under steady winds flowing through the turbine at a rate of 42,000 kg/s. The tip velocity o

zzz [600]

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

$r=\frac{v}{2\pi f}\\\Rightarrow r=\frac{250\div 3.6}{2\pi 0.25}=\frac{250}{1.8\pi}$

$A=\pi r^2\\\Rightarrow A=\pi\left(\frac{250}{1.8\pi}\right)^2\\\Rightarrow A=\left(\frac{250}{1.8}\right)^2\frac{1}{\pi}$

$m=\rho V\\\Rightarrow m=\rho vA\\\Rightarrow v=\frac{m}{\rho A}\\\Rightarrow v=\frac{42000}{1.31 \left(\frac{250}{1.8}\right)^2\frac{1}{\pi}}\\\Rightarrow v=5.22\ m/s$

∴ The average velocity of the air is 5.22 m/s

$E=m\frac{v^2}{2}=42000\frac{5.22^2}{2}\\\Rightarrow E=572538.92$

$\eta=\frac{W}{E}=\frac{180000}{572538.92}\\\Rightarrow \eta =0.314$

∴ Conversion efficiency of the turbine is 0.314 or 31.4 %

7 0

3 years ago

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Which of the following is not a mechanical form of energy?

taurus [48]

Answer:

The answer is Spring Potential

Explanation:

Because all the others are a mechanical form of energy

7 0

3 years ago

A scientist in Northern California is studying the tree rings of a very old redwood tree. He notices that the oldest tree rings

Studentka2010 [4]

Answer: colder and drier

Explanation:

Trees don’t grow well in wet climates, nor when they are cold. The wider the rings, the healthier the tree is. Since it was narrow and then wide, was bad climate and then good.

5 0

3 years ago

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a rod of zinc has a mass of 5kg. in water it weighs 25 N. what is the buoyant force on it when it is submerged in water?

Alexxandr [17]

Answer:

If it has a mass of 5 kg its weight is 5 kg * 9.8 m/s^2 = 49 N

Weight in air = 49 N

Weight in water = 25 N

Buoyant force provided by water = 49 - 25 = 24 N

7 0

3 years ago