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3 years ago

What happens to the speed of the electrons when the resistance is decreased?

Physics

1 answer:

3241004551 [841]3 years ago

7 0

Answer:

they slow down

Explanation:

Because number of electrons remain same in the closed circuit or wire, due to conservation of charge in any case. But due to addition of a external resistor current will decreases, by applying ohm's law( V=IR).

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What is the length of a pendulum with a period of one second?

worty [1.4K]

Answer:

A simple pendulum with a period of 1 second will have a length of 0.25 meters or 25 centimeters

Explanation:

hope it helps u☺☺

7 0

3 years ago

An electric drill

Lera25 [3.4K]

Answer:

Incomplete question. Complete question is: An electric drill starts from rest and rotates with a constant angular acceleration. After the drill has rotated through a certain angle, the magnitude of the centripetal acceleration of a point on the drill is twice the magnitude of the tangential acceleration. Determine the angle through which the drill rotates by this point.

The answer is : Δ θ = 1 rad

Explanation:

Ok, so the condition involves the centripetal acceleration and the tangential acceleration, so let’s start by writing expressions for each:

Ac= centripetal acceleration At= tangential acceleration

Ac = V² / r At = r α

Because we have to determine the angle ultimately, therefore we should convert the linear velocity into angular velocity in the expression for centripetal acceleration

V = r ω

Ac = (r ω)² / r = r² ω² / r

Ac = r ω²

now that we have expressions for the centripetal and tangential acceleration, we can write an equation that expresses the condition given: The magnitude of the centripetal acceleration is twice the magnitude of the tangential acceleration.

Ac = 2 At

That is,

r ω² = 2 r α

it is equivalent to;

ω² = 2 α

now we have the relation between angular speed and angular acceleration, but we also need to determine the angular displacement as well. Therefore choose a kinematics equation that doesn’t involve time because time is not mentioned in the question. Thus,

ω² – ω°² = 2 α Δ θ

such that ω° = 0

and ω² = 2 α

therefore;

2 α - 0 = 2 α Δ θ

2 α = 2 α Δ θ

So the angle will be : Δ θ = 1 rad

7 0

3 years ago

at certain times the demand for electric energy is low and electric energy is used to pump water to a reservoir 45 m above the g

Readme [11.4K]

The mass of water that must be raised is $5.25\cdot 10^7 kg$

Explanation:

Since the process is 70% efficiency, the power in output to the turbine can be written as

$P_{out} = 0.70 P_{in}$

where $P_{in}$ is the power in input.

The power in input can be written as

$P_{in} = \frac{W}{t}$

where

W is the work done in lifting the water

t = 3 h = 10,800 s is the time elapsed

The work done in lifting the water is given by

$W=mgh$

where

m is the mass of water

$g=9.8 m/s^2$ is the acceleration of gravity

h = 45 m is the height at which the water is lifted

Combining the three equations together, we get:

$P_{out} = 0.70 \frac{mgh}{t}$

Where

$P_{out} = 150 MW = 150\cdot 10^6 W$

And solving for m, we find:

$m=\frac{Pt}{0.70gh}=\frac{(1.50\cdot 10^6)(10800)}{(0.70)(9.8)(45)}=5.25\cdot 10^7 kg$

Learn more about power:

brainly.com/question/7956557

#LearnwithBrainly

3 0

4 years ago

An electron passes through two rectangular regions that contain uniform magnetic fields, B1 and B2. The field B1 is stronger tha

gtnhenbr [62]

Answer:

v1 = v2

Explanation:

Given:

- The missing figure is (attached).

- The Magnetic Field B1 > B2

Find:

How does the speed v1 of the electron in region 1 compare with the speed v2 in region 2?

Solution:

- From Lorentz Law we know that the Force that acts on the charge particle is the cross product of Magnetic Field Vector ( B1 or B2 ) and the velocity vector (v1 or v1).

- From the attached figure related to this problem we see that the electron velocity or direction of motion is always parallel to the magnetic field B1&B2.

- The law of cross product for parallel vector is 0. Hence, the Lorentz force acting on the electron is also zero.

- Zero Force means no work is done on the particle by the magnetic field, thus, the change in kinetic energy also zero for conservation of energy to hold.

- The initial and final kinetic energies of the electron is same. Hence, we can conclude that v1 = v2.

3 0

3 years ago

What are the elements of NaCl

Lana71 [14]

The elements in NaCl are Na -sodium and Cl - chlorine

<u>Explanation:</u>

sodium chloride (NaCl) is also known as common salt. The molar ratio of NaCl is 1:1 and has the molar mass of 22.99 and 35.45 respectively. The molar mass of NaCl is 58.443 g/mol. It is a odorless and colourless cubic crystal.

It has the melting point of 800.7°C and has the boiling point of 1465°C. It has a face centered cubic crystal structure.The elements in NaCl are Na -sodium and Cl - chlorine

$2Na+Cl_{2}$ → $2NaCl$

4 0

3 years ago