How long does it take for mitosis to complete?

A flock of ducks is trying to migrate south for the winter, but they keep being blown off course by a wind blowing from the west

Minchanka [31]

The ducks' flight path as observed by someone standing on the ground is the sum of the wind velocity and the ducks' velocity relative to the wind:

ducks (relative to wind) + wind (relative to Earth) = ducks (relative to Earth)

or equivalently,

$\vec v_{D/W}+\vec v_{W/E}=\vec v_{D/E}$

(see the attached graphic)

We have

ducks (relative to wind) = 7.0 m/s in some direction θ relative to the positive horizontal direction, or

$\vec v_{D/W}=\left(7.0\dfrac{\rm m}{\rm s}\right)(\cos\theta\,\vec\imath+\sin\theta\,\vec\jmath)$

wind (relative to Earth) = 5.0 m/s due East, or

$\vec v_{W/E}=\left(5.0\dfrac{\rm m}{\rm s}\right)(\cos0^\circ\,\vec\imath+\sin0^\circ\,\vec\jmath)$

ducks (relative to earth) = some speed v due South, or

$\vec v_{D/E}=v(\cos270^\circ\,\vec\imath+\sin270^\circ\,\vec\jmath)$

Then by setting components equal, we have

$\left(7.0\dfrac{\rm m}{\rm s}\right)\cos\theta+5.0\dfrac{\rm m}{\rm s}=0$

$\left(7.0\dfrac{\rm m}{\rm s}\right)\sin\theta=-v$

We only care about the direction for this question, which we get from the first equation:

$\left(7.0\dfrac{\rm m}{\rm s}\right)\cos\theta=-5.0\dfrac{\rm m}{\rm s}$

$\cos\theta=-\dfrac57$

$\theta=\cos^{-1}\left(-\dfrac57\right)\text{ OR }\theta=360^\circ-\cos^{-1}\left(-\dfrac57\right)$

or approximately 136º or 224º.

Only one of these directions must be correct. Choosing between them is a matter of picking the one that satisfies both equations. We want

$\left(7.0\dfrac{\rm m}{\rm s}\right)\sin\theta=-v$

which means θ must be between 180º and 360º (since angles in this range have negative sine).

So the ducks must fly (relative to the air) in a direction 224º relative to the positive horizontal direction, or about 44º South of West.

8 0

3 years ago

A lamp is 10% efficient. How much electrical energy must be supplied to the lamp each second if it produces 20 J of light energy

Leto [7]

Answer:

200J

Explanation:

200J is 100%, 10% of 200J would be 20J

3 0

3 years ago

What is life and how do we live it

Liono4ka [1.6K]

Life is what was given to us by what some people say is God. If you believe that, then your purpose is to live for him.

6 0

3 years ago

Read 2 more answers

Do all solids have any similar properties

Mamont248 [21]

Yes the molecules
are all compressed together

8 0

4 years ago

Is it a must that a nucleus must have opposite nature with the electron

Crazy boy [7]

Generally, the nucleus of an atom has a positive CHARGE because of the protons (not sure what you mean by nature) which helps attract the electrons the nucleus but it stays within it's electron cloud.

It cannot have the same charges as electrons (being negative) as the electrons would be repelled and the atom would lose it's structure.

I hope this answers the question.

7 0

3 years ago