Answer: 539.4 N
Explanation:
Let's begin by explaining that Coulomb's Law establishes the following:
"The electrostatic force
between two point charges
and
is proportional to the product of the charges and inversely proportional to the square of the distance
that separates them, and has the direction of the line that joins them"
What is written above is expressed mathematically as follows:
(1)
Where:
is the electrostatic force
is the Coulomb's constant
and
are the electric charges
is the separation distance between the charges
Then:
(2)
Isolating
and
:
(3)
Now, if we keep the same charges but we decrease the distance to
, (1) is rewritten as:
(4)
Then, the new electrostatic force will be:
(5) As we can see, the electrostatic force is increased when we decrease the distance between the charges.
H = 280 ft, the height of the flower pot.
g = 32 ft/s²
Neglect air resistance.
Note that 1 ft/s = 15/22 mi/h
The initial vertical velocity is zero.
Let v = the velocity with which the flower pot hits the ground.
Then
v² = 2gh
= 2*(32 ft/s²)*(280 ft)
= 17920 (ft/s)²
v = 133.866 ft/s
Also,
v = (133.866 ft/s)*(15/22 (mi/h)/(ft/s)) = 91.272 mi/h
Answer: 133.9 ft/s or 91.3 mi/h
You asked a question. I'm about to answer it.
Sadly, I can almost guarantee that you won't understand the solution.
This realization grieves me, but there is little I can do to change it.
My explanation will be the best of which I'm capable.
Here are the Physics facts I'll use in the solution:
-- "Apparent magnitude" means how bright the star appears to us.
-- "Absolute magnitude" means the how bright the star WOULD appear
if it were located 32.6 light years from us (10 parsecs).
-- A change of 5 magnitudes means a 100 times change in brightness,
so each magnitude means brightness is multiplied or divided by ⁵√100 .
That's about 2.512... .
-- Increasing magnitude means dimmer.
Decreasing magnitude means brighter.
+5 is 10 magnitudes dimmer than -5 .
-- Apparent brightness is inversely proportional to the square
of the distance from the source (just like gravity, sound, and
the force between charges).
That's all the Physics. The rest of the solution is just arithmetic.
____________________________________________________
-- The star in the question would appear M(-5) at a distance of
32.6 light years.
-- It actually appears as a M(+5). That's 10 magnitudes dimmer than M(-5),
because of being farther away than 32.6 light years.
-- 10 magnitudes dimmer is ( ⁵√100)⁻¹⁰ = (100)^(-2) .
-- But brightness varies as the inverse square of distance,
so that exponent is (negative double) the ratio of the distances,
and the actual distance to the star is
(32.6) · (100)^(1) light years
= (32.6) · (100) light years
= approx. 3,260 light years . (roughly 1,000 parsecs)
I'll have to confess that I haven't done one of these calculations
in over 50 years, and I'm not really that confident in my result.
If somebody's health or safety depended on it, or the success of
a space mission, then I'd be strongly recommending that you get
a second opinion.
But, quite frankly, I do feel that mine is worth the 5 points.
Explanation:
a. KE at bottom = PE at top
½ mv² = mgh
v = √(2gh)
v = √(2 × 9.8 m/s² × 20.0 m)
v = 19.8 m/s
b. Work by friction = PE at top
mgμ d = mgh
d = h / μ
d = 20.0 m / 0.210
d = 95.2 m
The Doppler Effect is the change in frequency or wavelength of a wave for an observer moving relative to its source. It is named after the Austrian physicist Christian Doppler.