1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
exis [7]
3 years ago
10

Assume that the moon is hit by about 25 million micrometeorite impacts each day, and that these impacts strike randomly around t

he moon's surface. also assume that after a footprint is hit by 20 micrometeorites it is erased. (a) roughly (order of magnitude) how long do we expect it would take, in years, for one of the footprints left by the apollo astronauts to be completely erased?
Physics
2 answers:
allsm [11]3 years ago
6 0

The time required for the footprint left by the Apollo astronaut to be erased is \fbox{\begin\\1010\,{\text{million}}\,{\text{yr}}\end{minispace}}.

Further explanation:

Some astronauts went to the moon to know about the moon. They walk on the surface of moon that’s why their footprints left there. It took time to erase the footprints.

Given:

The number of micrometeorites hitting the moon in one day is 25 \times {10^6}.

The area of footprint is 0.03\,{{\text{m}}^{\text{2}}}.

The surface area of moon is 3.79 \times {10^{19}}\,{{\text{m}}^{\text{2}}}.

Concept used:

When footprints hit the surface of moon it got impacted.

The expression for the number of micrometeorites hitting the surface area of footprints in one day is given as.

\fbox{\begin\\n = \dfrac{N}{{{A_{{\text{moon}}}}}}{A_{{\text{footprint}}}}\end{minispace}}                                   …… (1)

Here, N is the number of micrometeorites hitting the moon in one day, {A_{{\text{moon}}}} is the surface area of moon and {A_{{\text{footprint}}}} is the surface area of footprint.

The expression for the time to receive impacts on footprints.

\fbox{\begin\\T = \dfrac{{20}}{n}\end{minispace}}                                                                                 …… (2)

Substitute 25 \times {10^6} for N, 0.03\, {{\text{m}}^{\text{2}}} for {A_{{\text{footprint}}}} and in equation (1).

\begin{aligned}n &= \frac{{\left( {25 \times {{10}^6}} \right)}}{{\left( {3.79 \times {{10}^{19}}\,{{\text{m}}^{\text{2}}}}\right)}}\left({0.03\,{{\text{m}}^{\text{2}}}\right)\\&=1.979\times{10^{-8}}\\\end{aligned}

This means that the footprints receive 1.979 \times {10^{ - 8}} number of micrometeorites or impacts per day.

20 Impacts are required to erase the footprint in one day.

The expression for the time required to erase the footprints is given in equation (2).

Substitute 1.979 \times {10^{ - 8}}for n in equation (2).

\begin{aligned}T &= \frac{{20}}{{\left( {1.979 \times {{10}^{-8}}}\right)}}\\&=1.010\times{10^9}\,{\text{days}}\\\end{aligned}

Thus, it can be given in million years as \fbox{1010\,{\text{million}}\,{\text{yr}}}.

Learn more:

1.  Motion of ball under gravity brainly.com/question/10934170.

2.  Examples of wind and solar energy brainly.com/question/1062501.

3. Conservation of momentum brainly.com/question/9575487.

Answer Details:

Grade: College

Subject: Physics

Chapter: Astronomy  

Keywords:

Moon, meteorites, footprints, impact, surface area, 20 impacts, micrometeorites, 25 million  micrometeorites, 1010 million year,1.010*10^9 days .

defon3 years ago
3 0

Use the following formula to find the time meteorites take for a footprint to be erased:

T = [(Impact needed of a footprint)(4πr^2)]/[(impact rate)(Area of a footprint)].

 

Use the following formula to find the area of a foot:

Area of a foot = length of foot x width of foot

 

Substitute the given values in the above equation to get area of a foot:

Area of a foot = 25 cm x 10 cm = 250 cm^2

 

Convert the radius of moon in kilometers to centimeters.

R = 1738 km = 1738 km (10^5 cm / km) = 1.738 x 10^8 cm

 

The time meteorites take for a footprint to be erased:

T = (20)(4 π (1.738 x 10^8)^2) / (25 million / day) (250 cm^2) = 758.78 x 10^16 / 6250 x 10^6 /day = 1.21 x 10^9 days

 

Therefore, the time meteorites take for a footprint to be erased is 1.21 x 10^9 days

<span> </span>

You might be interested in
Cuando una persona sube y baja una escalera, Cuanto vale su desplazamiento y cual es la medida de su trayectoria.
adoni [48]

Answer:

Primero, definimos el desplazamiento como la distancia entre la posición final y la posición inicial.

Así, si comenzamos abajo, luego subimos la escalera, y luego bajamos, la posición final y la posición inicial serán la misma

por lo que el desplazamiento es igual a cero.

La medida recorrida es el espacio total recorrido.

Es decir, si entre el principio y el final de la escalera hay una distancia D.

La persona que sube y baja, recorre esta distancia dos veces.

Entonces cuando una persona sube y baja la escalera, la medida de su trayectoria será 2*D.

8 0
3 years ago
If the 80 ohm resistor fails, will the 50 ohm and 100 ohm resistor continue to operate? Why or why not?
sleet_krkn [62]

Answer:

No, the 50 ohm and 100 ohm resistor will not continue to operate.

Explanation:

A closed circuit is the circuit in which there is no break between the negative and the positive end of the battery.

When in this, combinational circuit the 80 ohm resistor fail then there will not any continue supply of current in the circuit due to the breakage because the electron will flow from negative end of the battery to positive end if their is no breaking in the circuit.

Therefore the 50 ohm and 100 ohm circuit will not continue to operate because of the breaking of the circuit and current will not flow.

7 0
3 years ago
A sample of an ideal gas is in a tank of constant volume. The sample absorbs heat energy so that its temperature changes from 33
Anuta_ua [19.1K]

Answer:

\frac{v_{2}}{v_{1}}=2.

Explanation:

The average kinetic energy per molecule of a ideal gas is given by:

\bar{K}=\frac{3k_{B}T}{2}

Now, we know that \bar{K} = (1/2)m\bar{v}^{2}

Before the absorption we have:

(1/2)m\bar{v_{1}}^{2}=\frac{3k_{B}T_{1}}{2} (1)

After the absorption,

(1/2)m\bar{v_{2}}^{2}=\frac{3k_{B}T_{2}}{2} (2)

If we want the ratio of v2/v1, let's divide the equation (2) by the equation (1)

\frac{v_{2}^{2}}{v_{1}^{2}}=\frac{T_{2}}{T_{1}}

\frac{v_{2}}{v_{1}}=\sqrt{\frac{T_{2}}{T_{1}}}

\frac{v_{2}}{v_{1}}=\sqrt{\frac{1340}{335}}

\frac{v_{2}}{v_{1}}=\sqrt{4}

Therefore the ratio will be \frac{v_{2}}{v_{1}}=2

I hope it helps you!

4 0
3 years ago
Read 2 more answers
Love waves arrival time ?
Anvisha [2.4K]
Boiii you better be more pasfic when you ask a question I don’t have any information about it I wanna was wyour one of the day
7 0
3 years ago
Read 2 more answers
Find the ratio of the gravitational force between two planets if the masses of both planets are quadrupled but the distance betw
Snezhnost [94]

Answer:

The ratio of the new force over the original force is 16

Explanation:

Recall the formula for the gravitational force between two masses M1 and M2 separated a distance D:

F_G=G\,\frac{M_1\,\,M_2}{D^2}

So now, if the masses M1 and M2 are quadrupled and the distance stays the same, the new force becomes:

F'_G=G\,\frac{4M_1\,\,4M_2}{D^2}=G\,\frac{16\,\,M_1\,\,M_2}{D^2}=16\,\,G\,\frac{M_1\,\,M_2}{D^2}= 16\,\,F_G

which is 16 times the original force.

So the ratio of the new force over the original force is 16

5 0
3 years ago
Other questions:
  • Mechanical (sound) waves are unable to travel through a vacuum, such as through space, but radio waves are transmitted to Earth
    14·2 answers
  • An overnight rainstorm has caused a major roadblock. Three massive rocks of mass m1=584 kg, m2=838 kg, and m3=322 kg have blocke
    9·1 answer
  • Two charges are separated by a distance 'd' and exert a mutual attractive force of 'f' on each other. if the distance is decreas
    11·1 answer
  • Plzzzzzzz help me quick
    11·1 answer
  • Calculate the length of a simple pendulum that oscillates with a frequency of 0.4Hz g=10m/s2 , ^=3.142
    12·1 answer
  • A person pushes a box across the floor the energy from the person moving arm is transferred to the box in the box in the floor b
    12·1 answer
  • if a person can jump 2m in earth surface how high can he jump in the moon (g of moon = 1.66m/s, g of earth = 9.8 m/s) [hint: use
    8·1 answer
  • 1 2 3 4 5 6 7 8 9 10
    5·2 answers
  • An organism has ____ copies of each gene.
    15·1 answer
  • A ball with an initial velocity of 5 m/s rolls off a horizontal table with a height of 1.0
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!