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Sophie [7]
2 years ago
9

As a descending elevator approaches the correct floor, it slows to a stop with a constant acceleration of magnitude 1m/s*2. The

elevator descends 4.5m while it is slowing. We want to find how many seconds the elevator takes to slow to a stop.
Which kinematic formula would be most useful to solve for the target unknown?

Physics
1 answer:
Nookie1986 [14]2 years ago
4 0

Answer:

C

Explanation:

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The wavelength of green light is 550 nm.
SIZIF [17.4K]

Answer:

(a) momentum of photon is 1.205 x 10⁻²⁷ kgm/s

    velocity of electron is 1323.88 m/s

   momentum of the electron is 1.205 x 10⁻²⁷ kgm/s

(b) momentum of photon is 1.506 x 10⁻²⁷ kgm/s

  velocity of electron is 1654.85 m/s

  momentum of the electron is 1.506 x 10⁻²⁷ kgm/s

(c) The momentum of the photon is equal to the momentum of the electron

Explanation:

(a)

wavelength of green light, λ = 550 nm

momentum of photon is given by;

p = \frac{h}{\lambda}\\\\ p = \frac{6.626 *10^{-34}}{550*10^{-9}}\\\\p = 1.205 *10^{-27} \ kg.m/s

velocity of electron is given by;

P = \frac{h}{\lambda} \\\\mv = \frac{h}{\lambda}\\\\v = \frac{h}{m \lambda}\\\\v =   \frac{6.626 *10^{-34}}{(9.1*10^{-31} )(550*10^{-9})}\\\\v = 1323.88 \ m/s

momentum of the electron is given by;

p = mv

p = (9.1 x 10⁻³¹) (1323.88)

p = 1.205 x 10⁻²⁷ kgm/s

(b)

wavelength of red light, λ = 440 nm

momentum of photon is given by;

p = \frac{h}{\lambda}\\\\ p = \frac{6.626 *10^{-34}}{440*10^{-9}}\\\\p = 1.506 *10^{-27} \ kg.m/s

velocity of electron is given by;

v =   \frac{6.626 *10^{-34}}{(9.1*10^{-31} )(440*10^{-9})}\\\\v = 1654.85 \ m/s

momentum of the electron is given by;

p = mv

p =  (9.1 x 10⁻³¹) (1654.85)

p = 1.506 x 10⁻²⁷ kgm/s

(c) The momentum of the photon is equal to the momentum of the electron.

7 0
2 years ago
The connections of many simple pieces in the brain is evidence of the:
olga55 [171]

Brian’s Complexity Brian’s Complexity Brian’s Complexity Brian’s Complexity

6 0
2 years ago
Read 2 more answers
A circular pipe of 25-mm outside diameter is placed in an airstream at 25C and 1-atm pressure. The air moves in cross flow over
kifflom [539]

Answer:

f_D = =3.24 N/m

Explanation:

data given

properties of air\nu\ of air =19.31*10^{-6} m2/s

\rho = 1.048 kg/m3

k = 0.0288 W/m.K

WE KNOW THAT

Reynold's number is given as

Re =\frac{VD}{\nu}

      = \frac{ 15*0.025}{19.31*10^{-6}}

      = 1.941 *10^4

drag coffecient is given as

C_D = \frac{f_D}{A_f\frac{\rho v^2}{2}}

solving for f_D

f_D = C_D A_f*\frac{\rho v^2}{2}

     =C_D D*\frac{\rho v^2}{2}

Drag coffecient for smooth circular cylinder is 1.1

therefore Drag force is

f_D = 1.1*0.025 *\frac{1.048*15^2}{2}

f_D = =3.24 N/m

4 0
2 years ago
A 2.5 g marshmallow is placed in one end of a 40 cm pipe, as shown in the figure above. A person blows into the left end of the
frosja888 [35]

Answer:

Your answer would be

A person 40 cm- blows into the left end of the pipe to eject the marshmallow from the right end. ... A strain of sound waves is propagated along an organ pipe and gets reflected from an. play · like-icon ... The velocity of sound in air is 340ms^(-1). ... The two pipes are submerged in sea water, arranged as shown in figure. Pipe.Explanation:

I belive this is the answer sorry if im wrong!

3 0
2 years ago
Read 2 more answers
An excited hydrogen atom releases an electromagnetic wave to return to its normal state. You use your futuristic dual electric/m
aniked [119]

Answer: The released electromagnetic wave will travel in +y direction

Explanation:

It should be noted that, in a situation, whereby an excited hydrogen atom releases an electromagnetic wave to return to its normal state. And it's also evident that the futuristic dual electric/magnetic field tester on the electromagnetic wave to find the directions of the electric field and magnetic field is used. Eventually, your device tells you that the electric field is pointing in the positive y direction and the magnetic field is pointing in the positive x direction. Therefore, the released electromagnetic wave will travel in +y direction.

7 0
2 years ago
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