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12345 [234]
3 years ago
15

The value of efficiency is never 100% or more in practice. why​

Physics
1 answer:
Alona [7]3 years ago
3 0

Answer: Because of presence of friction in most cases as friction exists in ever machine/body, so whenever it works, friction causes heat and sound energy as well, hence, proving that a system cannot be 100% efficient due to friction.

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An 20-cm-long Bicycle Crank Arm. With A Pedal At One End. Is Attached To A 25-cm-diameter Sprocket, The Toothed Disk Around Whic
malfutka [58]

To solve the problem, it is necessary to apply the concepts related to the kinematic equations of the description of angular movement.

The angular velocity can be described as

\omega_f = \omega_0 + \alpha t

Where,

\omega_f =Final Angular Velocity

\omega_0 =Initial Angular velocity

\alpha = Angular acceleration

t = time

The relation between the tangential acceleration is given as,

a = \alpha r

where,

r = radius.

PART A ) Using our values and replacing at the previous equation we have that

\omega_f = (94rpm)(\frac{2\pi rad}{60s})= 9.8436rad/s

\omega_0 = 63rpm(\frac{2\pi rad}{60s})= 6.5973rad/s

t = 11s

Replacing the previous equation with our values we have,

\omega_f = \omega_0 + \alpha t

9.8436 = 6.5973 + \alpha (11)

\alpha = \frac{9.8436- 6.5973}{11}

\alpha = 0.295rad/s^2

The tangential velocity then would be,

a = \alpha r

a = (0.295)(0.2)

a = 0.059m/s^2

Part B) To find the displacement as a function of angular velocity and angular acceleration regardless of time, we would use the equation

\omega_f^2=\omega_0^2+2\alpha\theta

Replacing with our values and re-arrange to find \theta,

\theta = \frac{\omega_f^2-\omega_0^2}{2\alpha}

\theta = \frac{9.8436^2-6.5973^2}{2*0.295}

\theta = 90.461rad

That is equal in revolution to

\theta = 90.461rad(\frac{1rev}{2\pi rad}) = 14.397rev

The linear displacement of the system is,

x = \theta*(2\pi*r)

x = 14.397*(2\pi*\frac{0.25}{2})

x = 11.3m

5 0
3 years ago
¿Hacia dónde se moverá el burro que se quiere sacar del corral jalándolo dos personas? La primer persona jala con 8 unidades de
dimaraw [331]

Answer:

sim eu também preciso desta respota

7 0
2 years ago
As mass increases what happens to the kinetic energy
AnnyKZ [126]
As mass increases kinetic energy also increases; kinetic energy is directly proportional to mass so whatever is done to either affects the other one the same. i hope this helps :)
5 0
3 years ago
Ivan pushes a dresser with full drawers across his carpeted floor. What could Ivan do to reduce the amount of friction between t
aniked [119]

Answer:

Place some smooth tiles under the dresser

Smooth surfaces, like smooth tile, are easy to slide over. They create very little friction. Rough surfaces like carpet create much more friction.

remove the drawers from the dresser

Weight affects friction in that friction is directly proportional to the weight of the load one is moving. So reduce the weight, reduce the friction.

Explanation:

Speed does not impact friction, so moving the dresser slower won't help. Wind has nothing to do with the scenario, so that's not a correct option.

7 0
2 years ago
Read 2 more answers
What humidity reading would be the driest?
Lunna [17]
The weather report never tells the "humidity" of the air.  It tells the
"RELATIVE humidity".  That's the percent of the moisture the air
COULD hold at the current temperature that it's actually holding
right now.

If the air is completely dry, then it's holding NONE of the moisture
that it COULD hold, and the relative humidity is zero percent.

7 0
3 years ago
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