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2 years ago

Where is the acceleration zero?

Physics

1 answer:

ladessa [460]2 years ago

3 0

Answer:

When acceleration is zero (that is, a = dv/dt = 0), rate of change of velocity is zero. That is, acceleration is zero when the velocity of the object is constant. so probably D

Explanation:

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two masses are separated by 1 m. suppose the masses are moved so they are 2 m apart how will the gravitational force change

Verdich [7]

The gravitational force would get stronger because the farther the two masses are separated the more gravitational force will be used to pull them together the closer they are the less gravitational pull is used to pull them together

5 0

3 years ago

Lasers are now used in eye surgery. Given the wavelength of a certain laser is 514 nm and the power of the laser is 1.1 W, how m

Leno4ka [110]

Answer: $1.593*10^{17} photons$ released if the laser is used 0.056 s during the surgery

Explanation:

First, you have to calculate the energy of each photon according to Einstein's theoty, given by:

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

Where $\lambda$ is the wavelength, $h$ is the Planck's constant and $h$ is the speed of light

$h = 6.626*10^{-34} \frac{m^{2} kg }{s}$ -> Planck's constant

$c = 3*10^{8} \frac{m}{s}$ -> Speed of light

So, replacing in the equation:

$E =\frac{ 6.626*10^{-34} \frac{m^{2} kg }{s}*3*10^{8} \frac{m}{s}}{514*10^-9 m}$

Then, the energy of each released photon by the laser is:

$E = 3.867*10^{-19} \frac{J}{photons}$

After, you do the inverse of the energy per phothon and as a result, you will have the number of photons in a Joule of energy:

$\frac{1}{3.867*10^{-19}} = 2.586*10^{18} \frac{photons}{J}$

The power of the laser is 1.1 W, or 1.1 J/s, that means that you can calculate how many photons the laser realease every second:

$2.586*10^{18}\frac{photons}{J} * 1.1 \frac{J}{s} = 2.844*10^{18} \frac{photons}{s}$

And by doing a simple rule of three, if $2.844*10^{18} photons$ are released every second, then in 0.056 s:

$0.056 s*2.844*10^{18} \frac{photons}{s} = 1.593*10^{17} photons$ are released during the surgery

5 0

3 years ago

Boyle’s Law: When____ is held constant, the pressure and volume of a gas are___ proportional.

Aleksandr-060686 [28]

Answer:

When temperature is held constant, the pressure and volume of a gas are not proportional.

Explanation:

That is Boyle's Law

7 0

3 years ago

Which of these factors will increase the speed of a sound wave in air?

Artemon [7]

<h3>Answer;</h3>

-Temperature

<h3><u>Explanation;</u></h3>

Sound is a type of mechanical wave, which means it requires a material medium for transmission. It results from the vibration of particles.
The speed of sound in mediums varies depending on the property of the medium and a number of other factors which includes; temperature, pressure, and humidity.
Temperature increases the speed of sound wave as particles at higher temperatures tend to possess more energy and thus they will vibrate faster and thus the sound wave will travel faster.

3 0

3 years ago

What is the momentum of a 15 kg tire rolling down a hill at 3 m/s? 5 kg • m/s 18 kg • m/s 45 kg • m/s 60 kg • m/s

maw [93]

p=mv

?=15kg * 3m/s

45p

7 0

3 years ago

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