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3 years ago

What statement is true according to newton’s first law of motion?

Physics

1 answer:

Airida [17]3 years ago

5 0

Answer:

c. in the absence of an unbalanced force, an object at rest will stay at rest and an object in motion will stay in motion.

Explanation:

First law: things keep doing what they are doing, unless force is applied.

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2. How does the medium vibrate in a transverse wave?

stiv31 [10]

ANSWER :

(A) AT RIGHT ANGLES TO THE DIRECTION THE WAVE TRAVELS.

EXPLANATION :

TRANSVERSE WAVES IS THAT IN WHICH THE PARTICLES VIBRATE WITH AN UP-AND-DOWN MOTION. THE PARTICLES IN A TRANSVERSE WAVE MOVE ACROSS OR PERPENDICULAR TO THE DIRECTION THAT THE WAVE IS TRAVELING OR AT RIGHT ANGLES TO THE DIRECTION THE WAVE TRAVELS.

3 0

3 years ago

An electron is trapped in a one-dimensional infinite well of width 340 pm and is in its ground state. What are the (a) longest,

Nesterboy [21]

Answer:

(a) 1.2703×10⁻⁷ m

(b) 4.7636×10⁻⁸ m

Explanation:

Given:

Width of the infinite well, L = 340 pm = 340×10⁻¹² m.

The formula for energy of the electron in nth state is:

$E_n=\frac {n^2\times h^2}{8mL^2}$

The expression for the difference in energy between the levels having quantum numbers n(initial) to n(final) is:

$\Delta E_n=\frac {({n_f}^2-{n_i}^2)\times h^2}{8mL^2}$

According to Planks theory:

E = hv

where, v is the frequency

Also,

Frequency×Wavelength = Speed of light

So,

$E=\frac {hc}{\lambda}$

$\lambda=\frac {hc}{E}$

Also, using energy from above formula as:

$\lambda=\frac {hc}{\frac {({n_f}^2-{n_i}^2)\times h^2}{8mL^2}}$

$\lambda=\frac {c\times {8mL^2}} {({n_f}^2-{n_i}^2)\times h}}$

For longest wavelength ni = 1 and nf = 2

m= mass of the electron = 9.1 ×10⁻³¹kg

c = 3×10⁸m/s

h = 6.625×10⁻³⁴J.sec

$\lambda_{Longest}=\frac {3\times 10^8\times {8\times 9.1\times 10^{-31}(340\times 10^{-12})^2}} {({2}^2-{1}^2)\times 6.625\times 10^{-34}}}$

Longest wavelength = 1.2703×10⁻⁷ m

For second longest wavelength ni = 1 and nf = 3

$\lambda_{Second\ Longest}=\frac {3\times 10^8\times {8\times 9.1\times 10^{-31}(340\times 10^{-12})^2}} {({3}^2-{1}^2)\times 6.625\times 10^{-34}}}$

Second longest wavelength = 4.7636×10⁻⁸ m

For third longest wavelength ni = 1 and nf = 4

$\lambda_{Third\ Longest}=\frac {3\times 10^8\times {8\times 9.1\times 10^{-31}(340\times 10^{-12})^2}} {({4}^2-{1}^2)\times 6.625\times 10^{-34}}}$

Third longest wavelength = 2.5406×10⁻⁸ m

3 0

3 years ago

Consider a transition at 5000 Å with a width of 1 Å and a cavity 2 cm3 in volume. How many electromagnetic modes exist in this f

Lena [83]

Answer:

total number of modes is 8

Explanation:

attached here is the calculations

3 0

3 years ago

CO2 , NaCl , HCl can be classified as ?

ExtremeBDS [4]

I suppose they can all be classified as compounds

4 0

3 years ago

PLease Help!

scoundrel [369]

Answer:

Option A is the correct answer.

Explanation:

The instantaneous acceleration = Change in velocity in velocity/Time taken

The slope of the graph should give instantaneous acceleration.

Slope of a graph = Change in value of Y -axis / Change in values of X -axis

Comparing both the equations

Change in value of Y -axis = Change in velocity in velocity

Change in values of X -axis = Time taken

So velocity values should be on the Y axis and Time values should be on the X axis.

Option A is the correct answer.

8 0

3 years ago