We use the formula,
Here, h is the variable represents the height of the flare in feet when it returns to the sea so, h = 0 and u is the initial velocity of the flare, in feet per second and its value of 192 ft/sec.
Substituting these values in above equation, we get
.
Here, t= 0 neglect because it is the time when the flare is launched.
Thus, flare return to the sea in 12 s.
Answer:
Answer:
Explanation:
Hello,
In this case, considering that the acceleration is computed as follows:
Whereas the final velocity is 28.82 m/s, the initial one is 0 m/s and the time is 4.2 s. Thus, the acceleration turns out:
Regards.
Answer: 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:
Where is the wavelength,
is the Planck's constant and
is the speed of light
-> Planck's constant
-> Speed of light
So, replacing in the equation:
Then, the energy of each released photon by the laser is:
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:
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:
And by doing a simple rule of three, if are released every second, then in 0.056 s:
are released during the surgery