To solve this problem it is necessary to apply the related concepts laser pulse energy.
By definition the energy of a laser pulse in terms of number of photons is
Where,
Wavelength
N = Number of photons in each laser pulse
h = Planck constant
c = Speed of light
We need to find the wavelength, then re-arrange the equation we have
Converting the unit the energy from J to eV, we have
Replacing,
Therefore the wavelength of the laser is 182.4nm
<em>Note: The Planck constant used is in units of eV.</em>
Here is something that you should read. According to this text, it says that "Natural convection is observed on an everyday basis where hot air (being less dense) rises up forcing the cooler air down." That is hw convection works.
Hope this helped!
Nate
Isaac Newton stated three laws of motion; the first law deals with forces<span> and ... Under </span>these<span> conditions the first law says that </span>if<span> an </span>object<span> is </span>not<span> pushed or pulled </span>
The train accelerates at the rate of 20 for some time, until it's just exactly
time to put on the brakes, decelerate at the rate of 100, and come to a
screeching stop after a total distance of exactly 2.7 km.
The speed it reaches while accelerating is exactly the speed it starts decelerating from.
Speed reached while accelerating = (acceleration-1) (Time-1) = .2 time-1
Speed started from to slow down = (acceleration-2) (Time-2) = 1 time-2
The speeds are equal.
.2 time-1 = 1 time-2
time-1 = 5 x time-2
It spends 5 times as long speeding up as it spends slowing down.
The distance it covers speeding up = 1/2 A (5T)-squared
= 0.1 x 25 T-squared = 2.5 T-squared.
The distance it covers slowing down = 1/2 A (T-squared)
= 0.5 T-squared.
Total distance = 2,700 meters.
(2.5 + .5) T-squared = 2,700
T-squared = 2700/3 = 900
T = 30 seconds
The train speeds up for 150 seconds, reaching a speed of 30 meters per sec
and covering 2,250 meters.
It then slows down for 30 seconds, covering 450 meters.
Total time = <u>180 sec</u> = 3 minutes, minimum.
Observation:
This solution is worth more than 5 points.