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3 years ago

8

A discharge lamp rated at 25 W (1 W = 1 J/s) emits yellow light of wavelength 580 nm. How many photons of yellow light does the

lamp generate in 1.0 s?

1 answer:

Scrat [10]3 years ago

3 0

Answer:

the number of photons of yellow light does the lamp generate in 1.0 s is 7 x $10^{19}$

Explanation:

given information:

power, P = 25 W

wavelength. λ - 580 nm = 5.80 x $10^{-7}$ m

time, t = 1 s

to calculate the number of photon(N), we use the following equation

N = λPt/hc

where

λ = wavelength (m)

P = power (W)

t = time interval (s)

h = Planck's constant (6.23 x $10^{-34}$ Js)

c = light's velocity (3 x $10^{8} m/s^{2}$ )

So,

N = λPt/hc

= (5.80 x $10^{-7}$ )(25)(1)/(6.23 x $10^{-34}$ )(3 x $10^{8} m/s^{2}$ )

= 7 x $10^{19}$

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A car accelerates in the +x direction from rest with a constant acceleration of a1 = 1.62 m/s2 for t1 = 20 s. At that point the

arsen [322]

Total displacement of the car: 405 m

Explanation:

The first part of the motion of the car is a uniformly accelerated motion, so we can use the suvat equation

$s_1=ut_1+\frac{1}{2}a_1 t_1^2$

where:

u = 0 is the initial velocity (the car starts from rest)

$t_1 = 20 s$ is the time elapsed in the 1st part

$a_1=1.62 m/s^2$ is the acceleration of the car in the 1st part

$s_1$ is the displacement of the car in the 1st part

Solving for $s_1$ ,

$s_1=0+\frac{1}{2}(1.62)(20)^2=324 m$

We can also find the velocity of the car after these 20 seconds using the equation:

$v_1 = u +a_1 t_1 = 0 + (1.62)(20)=32.4 m/s$

Now we can find the distance covered by the car in the 2nd part, where it decelerates after having seen the tree limb on the road. We can do it by using the suvat equation:

$s_2 = (\frac{v_1 + v_2}{2})t_2$

where:

$v_1=32.4 m/s$ is the initial velocity at the beginning of the 2nd phase

$v_2=0$ is the final velocity (the car comes to a stop)

$t_2=5 s$ is the time elapsed in the 2nd phase

Substituting,

$s_2=\frac{32.4+0}{2}(5)=81 m$

So, the total displacement of the car is

$s=s_1+s_2=324+81=405 m$

Learn more about accelerated motion:

brainly.com/question/9527152

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3 years ago

Which of these is a correct equation for force? A. F = m × a B. F = m ÷ a C. F = a ÷ m

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It would be f=ma so
a.
f=m <span>× a</span>

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3 years ago

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How many balls are there in a ski ball machine?

gtnhenbr [62]

Answer:

i think 2 per each sac

Explanation:

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Hope this helps

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3 years ago

If no heat is lost to the surroundings, how much heat must be added to raise the temperature from 20.0 ∘C to 85.0 ∘C ?

andrey2020 [161]

Answer:

Explanation:

$C_{water}$ = 4190 J/kg.K

$C_{Al}$ = 910 J/Kg. K

$m_{Al}$ = 1.50 kg

$m_{water}$ = 1.80 kg

$Q_{added} = Q_{Al} + Q_{water}$

$=m_{Al} C_{Al}$ ΔT + $m_{water} C_{water}$ ΔT

= (1.50)(910)(85.0-20)+(1.80)(4190)(85.0-20)

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4 years ago

A ball is dropped off the roof of a tall building. If the ball reaches the ground in 8 seconds, how tall is the building, in met

Ghella [55]

Let <em>b</em> be the height of the building, and <em>y</em> the height of the ball at time <em>t</em>, given by

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where <em>g</em> = 9.8 m/s² is the magnitude of the acceleration due to gravity.

It takes the ball 8 s to reach the ground, at which point <em>y</em> = 0, so that

0 = <em>b</em> - 1/2 (9.8 m/s²) (8 s)²

<em>b</em> = 1/2 (9.8 m/s²) (8 s)²

<em>b</em> = 313.6 m

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3 years ago