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Free_Kalibri [48]

2 years ago

14

The height of the Empire State Building is 318.00 meters. If a stone is dropped from the top of the building, what is the stone'

s velocity just before
it strikes the ground?

1 answer:

Svetlanka [38]2 years ago

4 0

Answer:

79

Explanation:

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The half-life of a certain radioactive substance is 12 hours. There are 19 grams present initially. a. Express the amount of su

neonofarm [45]

Answer:

(a) $N=19\times e^{-\lambda t}$

(b) 15 hours

Explanation:

half life, T = 12 hours

No = 19 g

(a) Let N be the amount remaining after time t.

Let λ be the decay constant.

$\lambda =\frac {0.6931}{T}$

The equation of radioactivity used here is given by

$N=N_{o}e^{-\lambda t}$

$N=19\times e^{-\lambda t}$

(b) N = 8 gram

Substitute the values in above equation

$\lambda =\frac {0.6931}{12}$

λ = 0.0577 per hour

So, $8=19\times e^{-0.577t}$

$e^{-0.0577t}=0.421$

Take natural log on both the sides

- 0.0577 t = - 0.865

t = 15 hours

4 0

3 years ago

All Physicsts over here plz help in these questions!!!!!!!!!

mrs_skeptik [129]

Hello!

First one we can use that PE=mgh so we have

4.37*10^5J/(9.12*10^3kg*9.80m/s^2)= 4.89m

Second one we can use Newton’s Second Law
F=ma and in this case F=mg so we have

g= 3.28*10^-2N/6*10^-3kg = 5.47m/s^2

Hope this helps. Any questions please ask. Thank you.

6 0

3 years ago

Read 2 more answers

X-rays with frequency 3 ⨉ 10 18 Hz shine on a crystal, producing an interference pattern. If the first bright spot is observed a

FrozenT [24]

Answer:

$5.1645\times 10^{-11}\ m$

Explanation:

n = Order = 1

c = Speed of light = $3\times 10^8\ m/s$

f = Frequency = $3\times 10^{18}\ Hz$

$\theta$ = Angle = $75.5^{\circ}$

Lattice spacing is given by

$d=\dfrac{n\lambda}{2\sin\theta}\\\Rightarrow d=\dfrac{n\times c}{f2\sin\theta}\\\Rightarrow d=\dfrac{1\times 3\times 10^{8}}{3\times 10^{18}\times 2\times \sin75.5^{\circ}}\\\Rightarrow d=5.1645\times 10^{-11}\ m$

The lattice spacing of the crystal is $5.1645\times 10^{-11}\ m$

6 0

3 years ago

Bohr analyzed the spectral lines of hydrogen.<br><br>true or false?

trasher [3.6K]

Answer:

I think it is false. Johann balmer analyzed the spectral lines of hydrogen

6 0

2 years ago

An ideal transformer has 60 turns in its primary coil and 360 turns in its secondary coil. If the input rms voltage for the 60-t

notka56 [123]

Answer:

720 V

Explanation:

Given that,

The number of turns in primary coil, N₁ = 60

The number of turns in secondary coil, N₂ = 360

The input rms voltage, V₁ = 120 V

We need to find the output rms voltage of the secondary coil . The relation between number of turns in primary coil - secondary coil to the input rms voltage to the output rms voltage is given by :

$\dfrac{N_1}{N_2}=\dfrac{V_1}{V_2}\\\\V_2=\dfrac{N_2V_1}{N_2}\\\\V_2=\dfrac{360\times 120}{60}\\\\V_2=720\ V$

<h3>So, the output rms voltage of the secondary coil is 720 V. Hence, the correct option is (b).</h3>

7 0

2 years ago