1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Kazeer [188]
2 years ago
10

Which of the following is an example of a pulley?

Engineering
2 answers:
alexira [117]2 years ago
3 0

Answer:

<em><u>Door knob</u></em>

Explanation:

When the knob on one side of the door is turned, the shaft retracts the spring-loaded latch that holds the door closed. Without the knob in place, more force would be needed to turn the shaft and retract the latch.

kirill [66]2 years ago
3 0
That is the correct answer
You might be interested in
Water at atmospheric pressure boils on the surface of a large horizontal copper tube. The heat flux is 90% of the critical value
masya89 [10]

Answer:

The tube surface temperature immediately after installation is 120.4°C and after prolonged service is 110.8°C

Explanation:

The properties of water at 100°C and 1 atm are:

pL = 957.9 kg/m³

pV = 0.596 kg/m³

ΔHL = 2257 kJ/kg

CpL = 4.217 kJ/kg K

uL = 279x10⁻⁶Ns/m²

KL = 0.68 W/m K

σ = 58.9x10³N/m

When the water boils on the surface its heat flux is:

q=0.149h_{fg} \rho _{v} (\frac{\sigma (\rho _{L}-\rho _{v})}{\rho _{v}^{2} }  )^{1/4} =0.149*2257*0.596*(\frac{58.9x10^{-3}*(957.9-0.596) }{0.596^{2} } )^{1/4} =18703.42W/m^{2}

For copper-water, the properties are:

Cfg = 0.0128

The heat flux is:

qn = 0.9 * 18703.42 = 16833.078 W/m²

q_{n} =uK(\frac{g(\rho_{L}-\rho _{v})     }{\sigma })^{1/2} (\frac{c_{pL}*deltaT }{c_{fg}h_{fg}Pr  } \\16833.078=279x10^{-6} *2257x10^{3} (\frac{9.8*(957.9-0.596)}{0.596} )^{1/2} *(\frac{4.127x10^{3}*delta-T }{0.0128*2257x10^{3}*1.76 } )^{3} \\delta-T=20.4

The tube surface temperature immediately after installation is:

Tinst = 100 + 20.4 = 120.4°C

For rough surfaces, Cfg = 0.0068. Using the same equation:

ΔT = 10.8°C

The tube surface temperature after prolonged service is:

Tprolo = 100 + 10.8 = 110.8°C

8 0
3 years ago
What is Back EMF? How does it limits the speed of a permanent magnet DC?
ss7ja [257]

Answer and Explanation:

The DC motor has coils inside it which produces magnetic field inside the coil and due to thus magnetic field an emf is induced ,this induced emf is known as back emf. The back emf always acts against the applied voltage. It is represented by E_b

The back emf of the DC motor is given by E_b=\frac{NP\Phi }{60A}

Here N is speed of the motor ,P signifies the number of  poles ,Z signifies the the total number of conductor  and A is number of parallel paths

As from the relation we can see that back emf and speed ar dependent on each other it means back emf limits the speed of DC motor

8 0
3 years ago
What should you release to re-establish vehicle control and tire traction?
MrMuchimi

Answer: The accelerator and the brakes.

6 0
2 years ago
Calculate the torque produced by a motor that has 500 windings across a 30cm diameter rotating core. The core is 0.6 M long insi
zalisa [80]

Answer:

hhjhfdddvhyyjjvfrryjjbcdryuj vdryujbcr4yug

7 0
3 years ago
For automobile engines, identify the best choice of motor oil.
Vlad1618 [11]

Answer:

C. Low viscosity for Maine in the winter and high viscosity for Florida in the summer.

Explanation:

The choice of motor oil or engine oil depends on the type of engine and also on the type of climate on which the engine runs.

In winter climates, we should use oil with low viscosity as at lower temperatures, the it flows more readily if its viscosity is low.

But the summer season needs a relatively thicker oil so as to reduce the thinning effect of the oil out of the engine.

Thus for Maine in the winter season, we need a low viscosity oil and for Florida a high viscosity oil in the summer season.

Therefore, option (c) is correct.

6 0
2 years ago
Other questions:
  • Does a thicker core make an electromagnet stronger?
    13·1 answer
  • A 14 inch diameter pipe is decreased in diameter by 2 inches through a contraction. The pressure entering the contraction is 28
    10·1 answer
  • What are the controlling LRFD load combinations for dead and floor live load?
    11·1 answer
  • How to find magnitude of forces
    8·1 answer
  • What are the prefixes for 1, 10, 1000, 1,000,000, .1, .01, .001, .000001
    9·1 answer
  • Water from an upper tank is drained into a lower tank through a 5 cm diameter iron pipe with roughness 2 mm. The entrance to the
    11·1 answer
  • Draw the six principal views of
    13·1 answer
  • Nothing. i have nothing to say but that. other than that im good. :))))
    14·1 answer
  • a motor has torque of 200 nm if i motors attached to an arm with a length of 25 cm and a string is too attached to the end appro
    13·1 answer
  • The density of a certain type of steel is 8.1 g/cm3. What is the mass of a 100 cm3 chunk of this steel
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!