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3 years ago

PARAPHRASE PLEASE

Physics

1 answer:

Vedmedyk [2.9K]3 years ago

5 0

The U.S. has highly important national security interest and economic hold in providing a reliable helium supply.

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In 1911, Ernest Rutherford and his assistants Geiger and Marsden conducted an experiment in which they scattered alpha particles

alexandr402 [8]

Answer:

Explanation:

We shall apply conservation of mechanical energy

kinetic energy of alpha particle is converted into electric potential energy.

1/2 mv² = k q₁q₂/d , d is closest distance

d = 2kq₁q₂ / mv²

= 2 x 9 x 10⁹ x 79e x 2e / 4mv²

= 1422 x2x (1.6 x 10⁻¹⁹)² x 10⁹ /4x 1.67 x 10⁻²⁷ x (1.5 x 10⁷)²

= 3640.32 x 10⁻²⁹ /2x 3.7575 x 10⁻¹³

= 484.4 x 10⁻¹⁶

=48.4 x 10⁻¹⁵ m

8 0

4 years ago

Which symbol and unit of measurement are used for electric current?

Burka [1]

Answer: Symbol is I and unit A

Explanation: A represents Amperes

HOPE THIS HELPS!!!!!!!!

4 0

3 years ago

Which of the following is the best reason for using a scanning electron microscope?

torisob [31]

Answer is C: Ability to see three-dimensional images of the surfaces of object

Explanation:

To enable the technician see fractures and broken particles in a better resolution as the SEM sees the peaks and valley of the structure.

8 0

3 years ago

A diffraction grating has 300 lines per mm. If light of wavelength 630 nm is sent through this grating, what is the highest orde

True [87]

Answer:

The order of maximum is $n = 5$

Explanation:

From the question we are told that

The diffraction grating is k = 300 lines per mm = 300000 lines per m

The wavelength is $\lambda = 630 \ nm = 630 *10^{-9} \ m$

Generally the condition for constructive interference is mathematically represented as

$dsin \theta = n * \lambda$

Here n is the order maximum

d is the distance the grating which is mathematically represented as

$d = \frac{1}{k}$

=> $d = \frac{1}{300000}$

=> $d = 3.3*10^{-6}\ m$

$n = \frac{dsin \theta}{ \lambda}$

at maximum $sin\theta = 1$

$n = \frac{d}{\lambda}$

=> $n = \frac{3.3*10^{-6}}{630 *10^{-9}}$

=> $n = 5$

8 0

3 years ago

A sound wave has a frequency of 645 Hz in air

rodikova [14]

Answer:

$-14.2^{\circ}C$

Explanation:

First of all, we can find the speed of the sound wave, which is given by:

$v=f \lambda$

where

f = 645 Hz is the frequency

$\lambda=0.5 m$ is the wavelength

Substituting,

$v=(645 Hz)(0.5 m)=322.5 m/s$

Now we can find the temperature of the air by using the following relationship:

$v = 331 m/s + 0.6 T$

where T is the temperature in Celsius degrees. Since we know v = 322.5 m/s, we can re-arrange the formula to find the temperature:

$T=\frac{v-331 m/s}{0.6}=\frac{322.5 m/s-331 m/s}{0.6}=-14.2^{\circ}C$

7 0

3 years ago