Ask question

Ask question

All categories

2 years ago

3

How were conditions on the early earth of more than three billion years ago different from those on today's earth? unlike earth

today, early earth _____?

1 answer:

Sergeeva-Olga [200]2 years ago

6 0

Only early Earth was intensely bombarded by space debris. The Earth today has an atmosphere thick enough to stop most of such debris.

You might be interested in

In Part 6.2.2, you will determine the wavelength of the laser by shining the laser beam on a "diffraction grating", a set of reg

harkovskaia [24]

Answer:

λ = 2042 nm

Explanation:

given data

screen distance d = 11 m

spot s = 4.5 cm = 4.5 × $10^{-2}$ m

separation L = 0.5 mm = 0.5 × $10^{-3}$ m

to find out

what is λ

solution

we will find first angle between first max and central bright

that is tan θ = s/d

tan θ = 4.5 × $10^{-2}$ / 11

θ = 0.234

and we know diffraction grating for max

L sinθ = mλ

here we know m = 1 so put all value and find λ

L sinθ = mλ

0.5 × $10^{-3}$ sin(0.234) = 1 λ

λ = 2042.02 × $10^{-9}$ m

λ = 2042 nm

3 0

2 years ago

An inclined plane is made out of a short plank of wood. It is used to move a 300N box up onto a tabletop 1m above the floor. Wha

Ronch [10]

Answer:

<em>The purpose of an inclinded plane is to make easier to move objects to a certain height.</em>

The technology behind this is about the Work you need to use to move the object upwards. Basically, when we use an inclined plane, we are splitting the net force, making easier to move. All this means, the force needed to move the objecto up will be lower, due to the inclined plane.

So, if the force needed is lower, then the work is also lower, because the work done is defined as the product between the force applied and the distance traveled.

<em>In addition, if we have a longer inclined plane, that means the force needed is even lower,</em> beacuse the distance is increased, but the Work is the same, because it only depends on the initial and final point.

Therefore, in this case, the work would remain the same and the mechanical advantage would increase. As we said before, the work needed will be the same despite the force decreases, because the distance increases, remaining the work as a constant. And the mechanical advantage increases, because it's easier to move if the inclined plane is longer.

3 0

2 years ago

Read 2 more answers

A square is 1.0 m on a side. Point charges of +4.0 μC are placed in two diagonally opposite corners. In the other two corners ar

finlep [7]

Answer:

<em>B) 1.0 × 10^5 V</em>

Explanation:

<u>Electric Potential Due To Point Charges </u>

The electric potential produced from a point charge Q at a distance r from the charge is

$\displaystyle V=k\frac{Q}{r}$

The total electric potential for a system of point charges is equal to the sum of their individual potentials. This is a scalar sum, so direction is not relevant.

We must compute the total electric potential in the center of the square. We need to know the distance from all the corners to the center. The diagonal of the square is

$d=\sqrt2 a$

where a is the length of the side.

The distance from any corner to the center is half the diagonal, thus

$\displaystyle r=\frac{d}{2}=\frac{a}{\sqrt{2}}$

$\displaystyle r=\frac{1}{\sqrt{2}}=0.707\ m$

The total potential is

$V_t=V_1+V_2+V_3+V_4$

Where V1 and V2 are produced by the +4\mu C charges and V3 and V4 are produced by the two opposite charges of $\pm 3\mu\ C$ . Since all the distances are equal, and the charges producing V3 and V4 are opposite, V3 and V4 cancel each other. We only need to compute V1 or V2, since they are equal, but they won't cancel.

$\displaystyle V_1=V_2=k\frac{Q}{r}=9\times 10^9 \frac{4\times 10^{-6}}{0.707}$

$V_1=V_2=50912\ V$

The total potential is

$V_t=50912\ V+50912\ V=1\times 10^5\ V$

$\boxed{V_t=1\times 10^5\ V}$

6 0

2 years ago

A small house was built on an island off a perfectly straight shoreline. The point B on the shoreline that is closest to the isl

abruzzese [7]

Answer:

Q should be 4.8 miles east of B.

Explanation:

As the diagram shows, we can simply express the construction cost as a function of angle θ (represented in the diagram).

The length of the pipe in water (represented with blue) = 6/cos θ

The length of the pipe on land (represented with brown) = (8-6*tan θ)

Construction Cost = (6/cos θ) (6000) + (8-6*tan θ)(3750)

The above function represents the construction cost and is in terms of θ

The value of θ varies from 0 degrees to 53.13 degrees as per the diagram.

We can take the derivative of Construction Cost function with respect to θ and equate it to zero to find the angle θ at which the construction cost is minimum.

d(Construction Cost)/d θ = -4500(5*sec θ – 8*tan θ)(sec θ)

-4500(5*sec θ – 8*tan θ) (sec θ) = 0

θ = 38.68 degrees

Using the value of θ, we can find the distance of Q from B.

Distance of Q from B = 6*tan θ

Distance of Q from B = 6*tan (38.68 degrees)

Distance of Q from B = 4.8 miles

7 0

2 years ago

A battery has some internal resistance. Can the potential difference across the terminals of the battery be equal to its emf.

yarga [219]

Answer:

yes, the potential difference across the terminals of the battery can be equal to its emf.

Explanation:

when the current in the battery is zero, meaning the current though, and hence the potential drop across the internal resistance is zero. This only happens when there is no load placed on the battery.

5 0

2 years ago