Answer:
Explanation:
Because we assume the pendulum is a "mathematical pendulum" (neglecting the moment of inertia of the bob), we can find:
By using the
The mean position is the position when <em>y</em> = 0, so:
rad/s
and in centimeters (cm).
Supposing the person has insignificant height, we have that the angle of elevation is connected to the height of rocket and distance from spectator by:
tan(θ) = H/D (opposite is height, adjacent is distance)
Taking the derivative of both sides with respect to time:
d/dt (tan(θ(t))) = v/D (where v is the velocity of the firework)
Using chain rule on the left side:
sec2(θ)*(dθ/dt) = v/D
dθ/dt = cos2(θ)*v/D
When the firework is 30 feet above the ground, θ = tan-1(30ft/15ft) = 0.540 rad
dθ/dt = [ 1 / (1 + 1) ]*(11)/15
= (1/2)(1/15)*(11)
= 11/100
= 0.011 radians /s
"Fiber-optic" is just a piece of GLASS with the thickness of a hair !
Glass is an insulator, and fiber-optic can't carry electrical current.
If you have an electronic signal ... like voice, music, video, bank data,
a dental X-ray, a cellphone call, a credit card charge, vital signs from
a patient in an ambulance, 20 TV channels to go up to a satellite ...
it has to be changed into a form that can travel through optical fiber.
The electronic signal is connected to a tiny tiny light bulb, or an LED,
or a LASER diode, and it makes the light blink in time to the electronic
signal. That LIGHT shines into one end of the optical fiber, and travels
several miles through the glass. At the other end, it's detected by a
photocell, and it gets turned back into an electronic signal again.
Where the question says "... a blank ..." up above, it's "... a light ..." .
Answer:
an inclined plane Makes easier to raise something heavy,like a rock. instead of lifting the rock straight up,you can raise it from its original Location with less force by pushing it up a ramp