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2 years ago

Randy wants to know whether a soil's porosity affects how easily seedlings grow in it.

2 answers:

4 0

Since the main objective of this experiment is to determine the effect of porosity on seedling growth that should be the only independent variable. In short, that is the only variable that should be different to ensure fair testing.

The answer should be B:

he plants seedlings in soils with different levels of porosity and equal levels of permeability.

Permeability is not what needs to be tested. If it changes, you may not be able to determine whether it was the porosity or permeability that cause changes.

Masteriza [31]2 years ago

3 0

Answer: B: different, equal

Explanation:

Since Randy wants to know how porosity affects seedling growth, he needs to design an experiment in which he uses soils of different porosity but keeps everything else the same. This means that his experiment should involve soils with equal levels of permeability, since this factor can also affect seedling growth. Randy is likely to find that most seedlings succeed in porous soils, because the open spaces between particles give them room to grow.

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Question 5 At 12:00 pm, a spaceship is at position ⎡⎣324⎤⎦ km ⎣ ⎢ ⎡ 3 2 4 ⎦ ⎥ ⎤ km away from the origin with respect to so

Anettt [7]

Answer:

[1, 6, -2]

Explanation:

Given the following :

Initial Position of spaceship : [3 2 4] km

Velocity of spaceship : [-1 2 - 3] km/hr

Location of ship after two hours have passed :

Distance moved by spaceship :

Velocity × time

[-1 2 -3] × 2 = [-2 4 -6]

Location of ship after two hours :

Initial position + distance moved

[3 2 4] + [-2 4 -6] = [3 + (-2)], [2 + 4], [4 + (-6)]

= [3-2, 2+4, 4-6] = [1, 6, -2]

4 0

2 years ago

Young athlete has a mass of 42 kg one day there is no wind shear and hundred metre race in 14.2 second a sketch graph not in ske

Fudgin [204]

Answer:

I don't get the question

8 0

1 year ago

Read 2 more answers

A ball of mass 0.4 kg is initially at rest on the ground. It is kicked and leaves the kicker's foot with a speed of 5.0 m/s in a

yawa3891 [41]

Answer:

the answer the correct is 3

Explanation:

Let's use the relationship between momentum and momentum

I = Δp

I = m $v_{f}$ - m v₀

Let's calculate

I = 0.4 5.0 - 0

I = 2.0 N s

By Newton's law of action and reaction the force on the ball is equal to the force that the ball exerts on the foot, therefore the impulse on the foot of equal magnitude, but in the opposite direction

I = 2.0 Ns with 60°

When reviewing the answer the correct is 3

4 0

2 years ago

At what distance above earth would a satellite have a period of 125 min?

Nezavi [6.7K]

Rw^2 = GmM/r^2
 Leads to
 w^2 r^3 = GM
 (2pi /T) ^2 r^3 = GM
 4pi^2 r^3 = GM T^2
 r^3 = GM T^2 / 4pi^2
 Work out r^3 then r.
 T = 125 min = 125(60) = 7500 s
 R = 6.38E6 m
 m = 5.97E24 kg
 G = 6.673E-11
 r= 8279791.78 m
Since r = radius R of Earth + height above urface,h
 h = r - R = 8279791.78 - 6.38E6 = 1899791.78 m
h= 1899.79178 Km

5 0

1 year ago

Read 2 more answers

Rank the following situations according to the magnitude of the impulse of the net force, from largest value to smallest value.

wolverine [178]

Answer:

I and II

III and IV

Explanation:

The impulse is equal to the change in momentum of the object involved, so we can calculate the change in momentum in each situation and compare them all.

Taking always east as positive direction, and labelling

u the initial velocity

v the final velocity

m = 1000 kg the mass (which is always equal)

We find:

(i)

u = 25 m/s

v = 0

$|I|=m(v-u)=(1000)(0-25)=25,000 Ns$

(II)

u = 25 m/s

v = 0

$|I|=m(v-u)=(1000)(0-25)=25,000 Ns$

(III)

In this case,

F = 2000 N is the force

$\Delta t = 10 s$ is the time

So the magnitude of the impulse is

$|I| =F\Delta t = (2000N)(10)=20,000 Ns$

(IV)

F = 2000 N is the force

$\Delta t = 10 s$ is the time

So the magnitude of the impulse is

$|I| =F\Delta t = (2000N)(10)=20,000 Ns$

(V)

u = 25 m/s

v = -25 m/s

$|I|=m(v-u)=(1000)(-25-25)=50,000 Ns$

So the ranking from largest to smallest is:

I and II

III and IV

5 0

2 years ago