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3 years ago

In every population there is variation. It is important that this variation.

Physics

1 answer:

Lady bird [3.3K]3 years ago

5 0

Answer:

Genetic variation is an important force in evolution as it allows natural selection to increase or decrease frequency of alleles already in the population.

rate the ans plz.

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Which instrument is used in submarine to see the objects above sea level ?

svetoff [14.1K]

Periscope i believe but i may be wrong.

8 0

3 years ago

Read 2 more answers

Problem 4 A meteoroid is first observed approaching the earth when it is 402,000 km from the center of the earth with a true ano

Nikitich [7]

Answer:

Part a: The eccentricity is 1.086.

Part b: The altitude at closest approach is 5088 km

Part c: The velocity at perigee is 8.516 km/s

Part d: The turn angle is 134.08 while the aiming radius is 5641.28 km

Explanation:

Specific energy is given by

$\epsilon=\frac{v^2}{2}-\frac{\mu}{r}$

Here

ε is the specific energy
v is the velocity which is given as 2.23 km/s
μ is the gravitational constant whose value is 398600
r is the distance between earth and the meteorite which is 402,000 km

$\epsilon=\frac{v^2}{2}-\frac{\mu}{r}\\\epsilon=\frac{2.2^2}{2}-\frac{398600}{402,000}\\\epsilon=1.495 km^2/s^2$

Value of specific energy is also given as

$\epsilon=\frac{\mu}{2a}\\a=\frac{\mu}{2\epsilon}\\a=\frac{398600}{2\times 1.495}\\a=13319 km$

Orbit formula is given as

$r=a(\frac{e^2-1}{1+ecos \theta})\\ae^2-recos\theta-(a+r)=0$

Putting values in this equation and solving for e via the quadratic formula gives

$ae^2-recos\theta-(a+r)=0\\(133319)e^2-(402000)(cos 150) e-(133319+402000)=0\\133319e^2+348142.21 e-535319=0\\\\e=\frac{-348142.21 \pm \sqrt{348142.21^2-4(133319)(535319)}}{2 (133319)}\\\\e=1.086 \, or \, -3.69$

As the value of eccentricity cannot be negative so the eccentricity is 1.086.

The radius of trajectory at perigee is given as

$r_p=a(e-1)\\$

Substituting values gives

$r_p=133319 (1.086-1)\\r_p=11465.4 km$

Now for estimation of altitude z above earth is given as

$z=r_p-R_E\\z=11465.4-6378\\z=5087.434\\z\approx 5088 km$

So the altitude at closest approach is 5088 km

radius of perigee is also given as

$r_p=\frac{h^2}{\mu}\frac{1}{1+e}$

Rearranging this equation gives

$h=\sqrt{r_p\mu(1+e)}\\h=\sqrt{11465.4 \times 3986000 \times (1+1.086)}\\h=97638.489 km^2/s$

Now the velocity at perigee is given as

$v_p=\frac{h}{r_p}\\v_p=\frac{97638.489}{11465.4}\\v_p=8.516 km/s\\$

So the velocity at perigee is 8.516 km/s

Turn angle is given as

$\delta =2 sin^{-1} (\frac{1}{e})$

Substituting value in the equation gives

$\delta =2 sin^{-1} (\frac{1}{e})\\\delta =2 sin^{-1} (\frac{1}{1.086})\\\delta =134.08$

Aiming radius is given as

$\Delta =a \sqrt{e^2-1}$

Substituting value in the equation gives

$\Delta =a \sqrt{e^2-1}\\\Delta =13319 \sqrt{1.086^2-1}\\\Delta=5641.28 km$

So the turn angle is 134.08 while the aiming radius is 5641.28 km

3 0

4 years ago

What is the atmospheric pressure of the U.S.

rusak2 [61]

When you say atmospheric pressure it is a standard on all places on earth. The value of standard atmospheric pressure is 1 Bar approximately or 14.7 lb per square inch. This pressure is an attribute of free molecules on the air which is not bound the accumulation of the pressure of this in average is the atmospheric pressure.

4 0

3 years ago

I don’t know how to explain this or if I am correct:(

Talja [164]

Answer:

c is correct

Explanation:

There are two equal forces on each sides of the rope. The greater opposing sides pull, the greater the magnitude of tension force along the rope.

4 0

3 years ago

The _____ is a variation of circuit training that alternates upper body and lower body exercises throughout the circuit.

IrinaK [193]

Answer:

peripheral heart action

Explanation:

The peripheral heart action is a variation of circuit training that alternates upper body and lower body exercises throughout the circuit.

Peripheral heart action practice is a method of interval bodybuilding training that was coined in the 1960s by former AAU Mr. America and Mr. Universe Bob Gajda. Most sources say that Gajda has always credited Arthur H. Steinhaus to create the concept behind PHA.

6 0

3 years ago