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3 years ago

Which option is the most accurate description of speed?

Physics

1 answer:

puteri [66]3 years ago

5 0

B I think is the answer

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Help me with this homework please

oee [108]

Answer:

100 N

Explanation:

From the question given above, the following data were obtained:

Mass (m) = 5 kg

Acceleration (a) = 20 m/s

Force (F) =?

Force is simply defined as the product of mass and acceleration. Mathematically, it can be expressed as:

Force (F) = mass (m) × acceleration (a)

F = ma

With the above formula, we can obtain the force need to move the object. This can be obtained as follow:

Mass (m) = 5 kg

Acceleration (a) = 20 m/s

Force (F) =?

F = ma

F = 5 × 20

F = 100 N

Therefore, a force of 100 N is needed to move the object.

3 0

3 years ago

What is the energy (in joules) and the wavelength (in meters) of the line in the spectrum of hydrogen that represents the moveme

soldi70 [24.7K]

Answer:

The energy is $4.57x10^{-19} J$ and the wavelength is $4.34x10^{-7}m$ for the line in the spectrum of hydrogen that represents the movement of an electron from Bohr orbit with n = 2 to the orbit with n = 5.

<em>In what part of the electromagnetic spectrum do we find this radiation? </em>

In the Ultraviolet part of the electromagnetic spectrum.

Explanation:

The energy of the absorbed photon can be known by the difference in energy between the two states in which the transition is happening (In this case from n = 2 to n = 5):

$E = E_{upper}-E_{lower}$ (1)

The permitted energy for the atom of hydrogen, according with the Bohr's model, is defined as:

$E_{n} = -\frac{13.606 eV}{n^{2}}$ (2)

Or it can be expressed in Joules, since $1eV = 1.60x10^{-19}J$

$E_{n} = -\frac{2.18x10^{-18} J}{n^{2}}$ (3)

Where the value $-2.18x10^{-18}$ represents the energy of the ground state¹ and n is the principal quantum number.

For the case of n = 2:

$E_{2} = -\frac{2.18x10^{-18} J}{(2)^{2}}$

$E_{2} = -5.45x10^{-19} J$

For the case of n = 5:

$E_{5} = -\frac{2.18x10^{-18} J}{(5)^{2}}$

$E_{5} = -8.72x10^{-20} J$

Replacing those values in equation (1) it is gotten:

$E = -8.72x10^{-20} J-(-5.45x10^{-19} J )$

$E = 4.57x10^{-19} J$

The wavelength can be determined by means of the Rydberg formula:

$\frac{1}{\lambda} = R(\frac{1}{n_{l}^{2}}-\frac{1}{n_{u}^{2}})$ (4)

Where R is the Rydberg constant, with a value of $1.097x10^{7}m^{-1}$

For this particular case $n_{l} = 2$ and $n_{u} = 5$ :

$\frac{1}{\lambda} = 1.097x10^{7}m^{-1}(\frac{1}{(2)^{2}}-\frac{1}{(5)^{2}})$

$\frac{1}{\lambda} = 1.097x10^{7}m^{-1}(0.21)$

$\frac{1}{\lambda} = 2303700m^{-1}$

$\lambda = \frac{1}{2303700m^{-1}}$

$\lambda = 4.34x10^{-7}m$

So the energy is $4.57x10^{-19} J$ and the wavelength is $4.34x10^{-7}m$ for the line in the spectrum of hydrogen that represents the movement of an electron from Bohr orbit with n = 2 to the orbit with n = 5.

<em>In what part of the electromagnetic spectrum do we find this radiation? </em>

In the Ultraviolet part of the electromagnetic spectrum.

Key terms:

¹Ground state: State of minimum energy.

8 0

3 years ago

What is the electric flux φ through each of the six faces of the cube? Use ϵ0 for the permittivity of free space?

exis [7]

If total charge Q is enclosed in the surface of cube

then we will have say that total flux linked with all surfaces of the cube will be given by

$\phi = \frac{Q}{\epsilon_0}$

since the position of charge is symmetric with respect to the center of the cube so here this whole flux will be equally linked with each of the face of the cube

So here total 6 faces of the cube is there and the total flux of the charge will equally divide in these 6 faces

so flux linked with each face is given by formula

$\phi = \frac{Q}{6\epsilon_0}$

so each face will have above flux due to central position of charge Q

3 0

3 years ago

Water drips from the nozzle of a shower onto the floor 189 cm below. The drops fall at regular (equal) intervals of time, the fi

laiz [17]

Answer:

0.83999 m

0.20999 m

Explanation:

g = Acceleration due to gravity = 9.81 m/s² = a

s = 189 cm

$s=ut+\frac{1}{2}at^2\\\Rightarrow 1.89=0t+\frac{1}{2}\times 9.81\times t^2\\\Rightarrow t=\sqrt{\frac{1.89\times 2}{9.81}}\\\Rightarrow t=0.62074\ s$

When the time intervals are equal, if four drops are falling then we have 3 time intervals.

So, the time interval is

$t'=\dfrac{t}{3}\\\Rightarrow t'=\dfrac{0.62074}{3}\\\Rightarrow t'=0.206913\ s$

For second drop time is given by

$t''=2t'\\\Rightarrow t''=2\times 0.2069133\\\Rightarrow t''=0.4138266\ s$

Distance from second drop

$s=ut+\dfrac{1}{2}at^2\\\Rightarrow y''=ut''+\dfrac{1}{2}at''^2\\\Rightarrow s=0\times t+\dfrac{1}{2}\times 9.81\times 0.4138266^2\\\Rightarrow s=0.839993\ m$

Distance from second drop is 0.83999 m

Distance from third drop

$s=ut+\dfrac{1}{2}at^2\\\Rightarrow y''=ut'+\dfrac{1}{2}at'^2\\\Rightarrow s=0\times t+\dfrac{1}{2}\times 9.81\times 0.206913^2\\\Rightarrow s=0.20999\ m$

Distance from third drop is 0.20999 m

6 0

4 years ago

The moon clearly exhibits a light and dark portion during most of the month except during full moon. What causes the dark portio

mylen [45]

While rotating around Earth the Moon also rotates around it's axis. These two rotations have almost same duration (27.3 and 27 days respectively). This is the reason why we always see the same side of Moon.

The dark part of a Moon is the part where there is night on the Moon, meaning there is no sunlight visible. This dark part depends on the Moon's position relative to Earth and Sun. The change in size is due to part of Moon-day. Dark part of Moon has night, bright part has day and the boundary has either sunrise or sunset.

8 0

3 years ago