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3 years ago

What makes astronomers think that impact rates for the Moon must have been higher earlier than 3.8 billion years ago?

1 answer:

3 0

There is strong evidence indicating that 3.8 billion years ago there was a higher impact rate. This deduction starts from comparing the number of craters in the lunar highlands with those of the Mary. If this comparison is made, it will be observed that there are 10 times more craters in the highlands than in a similar area of Mary. It should be borne in mind that through radioactive dating processes the samples indicate that there is a slightly greater antiquity in the highlands than those of Maria. This allows us to deduce that if the impact rates had been constant, the highlands would have been 10 times older. They would have to be formed 38 billion years ago, long before the universe itself began.

Therefore one of the most obvious reasons is there are ten times more craters on the older highlands than the Younger Maria.

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Force F acts between a pair of charges, q1 and q2, separated by a distance d. For each of the statements, use the drop-down menu

lora16 [44]

The initial force between the two charges is given by:

$F=k \frac{q_1 q_2}{d^2}$

where k is the Coulomb's constant, q1 and q2 the two charges, d their separation. Let's analyze now the other situations:

1. F

In this case, q1 is halved, q2 is doubled, but the distance between the charges remains d.

So, we have:

$q_1' = \frac{q_1}{2}\\q_2' = 2 q_2\\d' = d$

So, the new force is:

$F'=k \frac{q_1' q_2'}{d'^2}= k \frac{(\frac{q_1}{2})(2q_2)}{d^2}=k \frac{q_1 q_2}{d^2}=F$

So the force has not changed.

2. F/4

In this case, q1 and q2 are unchanged. The distance between the charges is doubled to 2d.

So, we have:

$q_1' = q_1\\q_2' = q_2\\d' = 2d$

So, the new force is:

$F'=k \frac{q_1' q_2'}{d'^2}= k \frac{q_1 q_2)}{(2d)^2}=\frac{1}{4} k \frac{q_1 q_2}{d^2}=\frac{F}{4}$

So the force has decreased by a factor 4.

3. 6F

In this case, q1 is doubled and q2 is tripled. The distance between the charges remains d.

So, we have:

$q_1' = 2 q_1\\q_2' = 3 q_2\\d' = d$

So, the new force is:

$F'=k \frac{q_1' q_2'}{d'^2}= k \frac{(2 q_1)(3 q_2)}{d^2}=6 k \frac{q_1 q_2}{d^2}=6F$

So the force has increased by a factor 6.

8 0

3 years ago

Read 2 more answers

A satellite orbits a planet of unknown mass in a circular orbit of radius 2.3 x 104 km. The gravitational force on the satellite

sladkih [1.3K]

Answer:

The kinetic energy is $KE = 7.59 *10^{10} \ J$

Explanation:

From the question we are told that

The radius of the orbit is $r = 2.3 *10^{4} \ km = 2.3 *10^{7} \ m$

The gravitational force is $F_g = 6600 \ N$

The kinetic energy of the satellite is mathematically represented as

$KE = \frac{1}{2} * mv^2$

where v is the speed of the satellite which is mathematically represented as

$v = \sqrt{\frac{G M}{r^2} }$

=> $v^2 = \frac{GM }{r}$

substituting this into the equation

$KE = \frac{ 1}{2} *\frac{GMm}{r}$

Now the gravitational force of the planet is mathematically represented as

$F_g = \frac{GMm}{r^2}$

Where M is the mass of the planet and m is the mass of the satellite

Now looking at the formula for KE we see that we can represent it as

$KE = \frac{ 1}{2} *[\frac{GMm}{r^2}] * r$

=> $KE = \frac{ 1}{2} *F_g * r$

substituting values

$KE = \frac{ 1}{2} *6600 * 2.3*10^{7}$

$KE = 7.59 *10^{10} \ J$

7 0

3 years ago

A charge of 5.0 coulombs moves through a circuit in 0.50 second. What is the current in the circuit

user100 [1]

Answer:

Explanation:

i = 5/.5 = 10 Amps. Hope this helps :)

6 0

3 years ago

Which of the following is not an indication of a chemical reaction? a substance dissolves formation of a precipitate color chang

SVETLANKA909090 [29]

a substance dissolves.

like adding a soluble salt to water, it just dissolves, i.e dissociates homogeneously as water is able to dissociate salts (ionic compounds) into its ions. (it can also dissociate other non-ionic compounds like HCL)

the salt still remains chemically as a salt and is unchanged chemically thus it is not an indication of a chemical reaction as no chemical reaction has taken place.

the formation of a precipitate is a chemical reaction because a new substance (i.e new chemical) is formed. For example adding aqueous sodium hydroxide into an aqueous solution with CU2+ cations will form a blue precipitate (that is copper (II) hydroxide which is insoluble, hence it precipitates). Since a new chemical is formed, a chemical reaction has taken place and thus indicates a chemical reaction.

color change... im not sure but usually a color change will only occur when a new substance is formed. Like iron corrodes (i.e rust) slowly in moist air to form hydrated iron (III) oxide that is rust. (brown color).

usually adding a mixture to a mixture has little energy change, i.e little heat taken in by the reaction mixture or little heat given out by the reaction mixture. Whereas when a new substance is formed, there is usually noticeable energy change like the container gets colder or hotter (without heat being supplied of course). For example dissolving basic oxides into water releases energy ( more energy released than gained = exothermic reaction).

i think that should be the answer... hope it helped :D

4 0

3 years ago

Read 2 more answers

What determines how long it takes for the capacitor to charge?

myrzilka [38]

The time constant determines how long it takes for the capacitor to charge.

To find the answer, we have to know more about the time constant of the capacitor.

<h3>What is time constant?</h3>

The time it takes for a capacitor to discharge 36.8% of its charge in a discharging circuit or charge up to 63.2% of its maximum capacity in a charging circuit, given that it has no initial charge, is the time constant of a resistor-capacitor series combination.
The circuit's reaction to a step-up (or constant) voltage input is likewise determined by the time constant.
As a result, the time constant determines the circuit's cutoff frequency.

Thus, we can conclude that, the time constant determines how long it takes for the capacitor to charge.

Learn more about the time constant here:

brainly.com/question/17050299

#SPJ4

6 0

2 years ago