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3 years ago

Which phenomenon generates electric current?

Physics

2 answers:

Dimas [21]3 years ago

7 0

Answer:

D Photoelectric effect

Explanation:

When light of a certain frequency which is above the cut off frequency is incident on a metal, electrons are emitted from its surface. These electrons are called photo electrons. The number of photo electrons released will depend on the intensity of the incident light. This flow or release of electrons develops an emf and is called as the photoelectric current.

Applications of photoelectric current include photo conductive cells, photoemissive cells, solar cells etc.

grigory [225]3 years ago

3 0

The one that does that is the photoelectric effect. This allows the sun to hit the surface and produces enough energy for electrons to be knocked off the atom and allows a current to move.

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Acceleration increases over time once a force is applied to the object. Given a force of 10.0 Newtons, which mass will have the

Zolol [24]

Mass is indirectly proportional to acceleration, so, lighter the object greater would be it's acceleration...

A) 0.10 kg is lightest among them, so it's your answer

6 0

3 years ago

Read 2 more answers

A wind turbine is rotating counterclockwise at 0.626 rev/s and slows to a stop in 12.9 s. Its blades are 17.9 m in length. What

iogann1982 [59]

Answer:

276.5 m/s^2

Explanation:

The initial angular velocity of the turbine is

$\omega=0.626 rev/s \cdot 2\pi rad/rev =3.93 rad/s$

The length of the blade is

r = 17.9 m

So the centripetal acceleration is given by

$a=\omega^2 r$

At the instant t = 0,

$\omega=3.93 rad/s$

So the centripetal acceleration of the tip of the blades is

$a=(3.93 rad/s)^2 (17.9 m)=276.5 m/s^2$

5 0

2 years ago

What is physical change ?

ss7ja [257]

Answer:

A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible. The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.

3 0

2 years ago

A machine that operates a ride at the fair requires 2500 J to lift a 294 N child 5.0 m. What is the efficiency of this machine?

NeX [460]

Answer:

η = 58.8%

Explanation:

Work is defined as the force applied by the distance traveled by the body.

$W =F*d$

where:

W = work [J] (units of joules)

F = force = 294 [N]

d = distance = 5 [m]

$W = 294*5\\W = 1470 [J]\\$

Efficiency is defined as the energy required to perform an activity in relation to the energy actually added to perform some activity. This can be better understood by means of the following equation.

$efficiency = W_{done}/W_{required}\\efficiency = 1470/2500\\efficiency = 0.588 = 58.8%$