Data:
u=0 m/s is the initial velocity of the plane
v=62 m/s is the final velocity of the plane (at which the plane takes off)
a=1.7 m/s^2 is the acceleration of the plane
To find the minimum distance S the plane needs to take off, we can use the following equation:
Re-arranging it and substituting the numbers, we find
Answer: Linear speed is 1,670 Kph.
Explanation:
If we assume that the earth is a perfect sphere, and that is spinning itself once every roughly 24 hr, we can get the angular velocity of the Earth, in magnitude, as follows:
ω = 2π / 24 Hr
Now, by definition, an angle is the relationship between the arc s, and the radius r, so we can replace these values in the angular velocity expression, as follows:
ω = (Δs / r) . 1/Δt ⇒ ω = (Δs/Δt). 1/r
But, by definition, Δs/At, is just the linear velocity, v, so we can conclude the following;
ω = v/r ⇒ v = ω. r
So, we can get v, as follows:
v = 2π /24 hr . 6378 Km = 1,670 Km/hr.
The process you're fishing for is "polarization", but that's a
misleading description.
Polarization doesn't do anything to change the light waves.
It simply filters out (absorbs, as with a polarizing filter) the
light waves that aren't vibrating in the desired plane, and
allows only those that are to pass.
The intensity of a light beam is always reduced after
polarizing it, because much (most) of the original light
has been removed.
A laser light source may be thought of as an exception,
since everything coming out of the laser is polarized.
1). The equation is: (speed) = (frequency) x (wavelength)
Speed = (256 Hz) x (1.3 m) = 332.8 meters per second
2). If the instrument is played louder, the amplitude of the waves increases.
On the oscilloscope, they would appear larger from top to bottom, but the
horizontal size of each wave doesn't change.
If the instrument is played at a higher pitch, then the waves become shorter,
because 'pitch' is directly related to the frequency of the waves, and higher
pitch means higher frequency and more waves in any period of time.
If the instrument plays louder and at higher pitch, the waves on the scope
become taller and there are more of them across the screen.
3). The equation is: Frequency = (speed) / (wavelength)
(Notice that this is exactly the same as the equation up above in question #1,
only with each side of that one divided by 'wavelength'.)
Frequency = 300,000,000 meters per second / 1,500 meters = 200,000 per second.
That's ' 200 k Hz ' .
Note:
I didn't think anybody broadcasts at 200 kHz, so I looked up BBC Radio 4
on-line, and I was surprised. They broadcast on several different frequencies,
and one of them is 198 kHz !
F = 750 N (Force)
d = 10 m (displacement
)
t = 25 s (time)
L = ? (Mechanical work
) = (Energy)
P = ? (Power)
Solve:
L = F × d = 750 × 10 = 7500 Joules
P = L / t = 7500 / 25 = 300 Watts
