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3 years ago

An insulated lunch bag keeps food warm by

Physics

2 answers:

Akimi4 [234]3 years ago

8 0

Answer: D

slowing the transfer of thermal energy from the food inside the bag to the air outside the bag.

strojnjashka [21]3 years ago

5 0

Trapping warm air in and keeping cold air out

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Find V. in the circuit of the following figure:

Angelina_Jolie [31]

Answer:

where is the figure

Explanation:

8 0

3 years ago

I have no clue on how to do this

KatRina [158]

a)5m/s b)5

the 5 is because you add the seconds to get 8 seconds and then do the same with the distance to get 40. 40/8 = 5. speed = 5

Velocity = displacement/change in time

V = 40/8

I just realized how unorganised my math looks but I hope this is helpfull

3 0

3 years ago

PLEASE HURRY HELP ME take 40 point please help me now.Just look The picture

kaheart [24]

Answer:

ion channel

Explanation:

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7 0

3 years ago

An electron is projected with an initial speed vi = 4.60 × 105 m/s directly toward a very distant proton that is at rest. Becaus

frutty [35]

Answer:

$2.99\times 10^{-19}\ m$

Explanation:

<u>Given:</u>

$u$ = initial velocity of the electron = $4.60\times 10^5\ m/s$

$v$ = final velocity of the electron = $3u$

$x$ = initial position of the electron from the proton = very distant = $\infty$

<u>Assume:</u>

$m$ = mass of an electron = $9.1\times10^{-31}\ kg$

$e$ = magnitude of charge on an electron = $1.6\times10^{-19}\ C$

$p$ = magnitude of charge on an proton = $1.6\times10^{-19}\ C$

$k$ = Boltzmann constant = $9\times 10^9\ Nm^2/C^2$

$y$ = final position of the electron from the proton

$\Delta K$ = change in kinetic energy of the electron

$W$ = work done by the electrostatic force

$F$ = electrostatic force

$r$ = instantaneous distance of the electron from the proton

Let us first calculate the work done by the electrostatic force.

$W=\int Fdr\\\Rightarrow W = \int \dfrac{kep}{r^2}dr\\\Rightarrow W = kep\int \dfrac{1}{r^2}dr\\\Rightarrow W = kep\left | \dfrac{1}{r} \right |_{y}^{x}\\\Rightarrow W = kep\left ( \dfrac{1}{x}-\dfrac{1}{y} \right )\\\Rightarrow W = kep\left ( \dfrac{1}{x}-\dfrac{1}{\infty} \right )\\\Rightarrow W =\dfrac{kep}{x}$

Using the principle of the work-energy theorem,

As only the electrostatic force is assumed to act between the two charges, the kinetic energy change of the electron will be equal to the work done by the electrostatic force on the electron due to proton.

$\therefore \Delta K = W\\\Rightarrow \dfrac{1}{2}m(v^2-u^2)= \dfrac{kep}{x}\\\Rightarrow \dfrac{1}{2}m((3u)^2-u^2)= \dfrac{kep}{x}\\\Rightarrow \dfrac{1}{2}m(8u^2)= \dfrac{kep}{x}\\\Rightarrow x= \dfrac{2kep}{8mu^2}\\\Rightarrow x= \dfrac{2\times 9\times 10^9\times 1.6\times10^{-19}\times 1.6\times10^{-19}}{8\times 9.1\times10^{-31}\times (4.60\times 10^5)^2}\\\Rightarrow x=2.99\times 10^{-10}\ m\leq$

Hence, the electron is at a distance of $2.99\times 10^{-10}\ m$ when the electron instantaneously has speed of three times the initial speed.

8 0

4 years ago

Describe what happens when your circuit is completed. Tap on one of the wires with your mouse. Describe what happens. Explain yo

klemol [59]

Answer: when a circuit is completed (it allows the flow of electrons which causes the light bulb to produce light).

Explanation:

A circuit is described as an electrical setup that is consists of a light bulb, a switch, a wire, a battery which is arranged to allow the flow of electric current. The major components of the electrical circuit includes:

--> The BATTERY which is the source of voltage to the circuit,

--> the WIRE which is the conductive path,

--> the LIGHT BULB which is the load that needs electrical power to operate and

--> the SWITCH which is the controller.

When a circuit is COMPLETED when electrons can flow from one end of a battery all the way around, through the wires, to the other end of the battery. Along its way, it will carry electrons to electrical objects that are connected to it like the light bulb and make it to produce light.

There are different types of electric circuit which are designed to create a conductive path of current or electricity. They include:

--> closed circuit

--> open circuit

--> short circuit

--> parallel circuit

--> series circuit.

6 0

3 years ago