6.4.2 Practice; Electricity & Magnetism N_Cruz

[ndan...@gmail.com]

6.4.2 Practice: Electricity and Magnetism

Practice Assignment
Physical Science (S1744040)

Nestor Cruz
Points possible: 50

Date: 12/18/12


Static Electricity
1. One of the Mars Rover vehicles, Sojourner, collected red Martian dust on its wheels as it rolled along. There is very little water on Mars, so it's not mud; it's actually dust. Explain, in detail, why the dust clings to the wheels. Be sure to describe forces by name and mention charging by induction, conducting, or rubbing, if it is appropriate. Also explain what atoms on Mars must be composed of. (4 points)

The static cling causes the dust to cling to all four wheels of the mars rover vehicle. The dust and the vehicle are opposites so they attract.



2. On Earth, electrical systems are usually "grounded," giving excess electrons a place to go. Household wiring has a "ground," literally a big metal stake pounded several yards into the ground. The stake is driven deep into Earth because, in most locations, soil is damp once you get several feet underground. Explain why damp soil helps the excess electrons move. (4 points)

When soil is damp, it contains water. Where there is water, energy is conducted which helps the electrons move around.



3. Keep in mind that Mars is dry (so is the moon). Why do you think scientists are concerned that static electricity will be a much bigger problem for astronauts than it is for people here on Earth? (4 points)

The drier the climate the more present static electricity is. The soil is so dry and if an astronaut were to walk on it a lightning bolt would zap his electrons.



4. In the future, as astronauts walk across the Martian surface, they will acquire a static charge.
A. What will this create around them? (2 points)

It will create an electric field.



B. If they accumulate a lot of charge, what might happen to sensitive electronics (in air locks, perhaps) as the astronaut approaches? (2 points)

The charge may send a bolt of lightning to the electrons and fry all of them.



Current and Circuits:
5. Fuel, like diesel and propane, is too heavy for the Mars mission to carry much, if any, of it. So power is likely to be provided by a solar array instead of a generator. The energy collected from the solar arrays will be stored in large battery banks. Most of the circuits will have a load of about 12 Ω. If 4 A is needed to run the equipment, what voltage does the battery bank need to be? (4 points)

48v=12^4b or 48v=20,736b



6. Design these circuits for use at the Mars station. Show sketches of the circuit. Then complete the math. (12 points)
A. A 12-V battery, running a motor. There's also a switch in the circuit so the motor can be turned on and off. Show this, too. If the motor has a resistance of 12 Ω, how much current goes through the motor? (4 points)

For every one amp= 12/12













B. One 24-V battery, charging up the Mars Rover. If the Rover has 120 ohms of resistance, how much current flows through it? (4 points)

for every 2 amps= 24/120 or 2a=0.2













C. Four 12-V batteries, combined to produce a total of 48 volts of potential, running the heating system. (On a warm day, it might reach 60°F on Mars!) This circuit needs a circuit breaker, represented as a resistor. So put one in.
What is the voltage difference across the heater? If the heater has a 12 Ω resistance, how much current goes through it? (4 points)

48 across the heater and 4a through the heater would be 48/12














Magnetism
7. The floors of the future Mars Station will be metal-stainless steel, in fact. The gravity on Mars is about one-third of that on Earth, so when the astronauts walk they will bounce along.
A. To keep them from bobbing so much, what can they do to the bottoms of their boots? (2 points)

add magnets to the bottom of the boots



B. One of the future astronauts must extend a probe outside the station to monitor the atmosphere every hour. But she gets tired of manually pushing out the probe extension every hour. She has access to batteries, some wire, some iron, a timed switch, and some permanent magnets. What can she make so that she doesn't have to operate the probe by hand every hour? What purpose does the timed switch serve? (6 points)

the electric switch that allows all connected devices to receive and get power.



C. As the teams start exploring the surface of Mars in the future, they will notice that they cannot use compasses for navigation. What is necessary for a compass to work as a navigation tool? Since compasses do not work on Mars, what can you conclude is true of Mars? (6 points)

No, it should not because mars doenst have a magnetic field like earth's that is generated by the core.



8. During severe dust storms, when the dust swirls like a tornado, the Mars station will not be able to send or receive communication signals. All they will hear is static. Considering that wireless communications are electromagnetic in nature, why do you think this would occur? (4 points)

Sand storms cause a lot of the static electricity from all of the tiny dust particles rubbing together and it would completely block the electromagnetic transmission.

[Williams, Sue]

30 out of 50 points

On Tue, Dec 18, 2012 at 1:18 PM, <ndan...@gmail.com> wrote:

6.4.2 Practice: Electricity and Magnetism

Practice Assignment
Physical Science (S1744040)

Nestor Cruz
Points possible: 50

Date: 12/18/12


Static Electricity
1. One of the Mars Rover vehicles, Sojourner, collected red Martian dust on its wheels as it rolled along. There is very little water on Mars, so it's not mud; it's actually dust. Explain, in detail, why the dust clings to the wheels. Be sure to describe forces by name and mention charging by induction, conducting, or rubbing, if it is appropriate. Also explain what atoms on Mars must be composed of. (4 points)

The static cling causes the dust to cling to all four wheels of the mars rover vehicle. The dust and the vehicle are opposites so they attract.

     2 points

2. On Earth, electrical systems are usually "grounded," giving excess electrons a place to go. Household wiring has a "ground," literally a big metal stake pounded several yards into the ground. The stake is driven deep into Earth because, in most locations, soil is damp once you get several feet underground. Explain why damp soil helps the excess electrons move. (4 points)

When soil is damp, it contains water. Where there is water, energy is conducted which helps the electrons move around.

     4 points

3. Keep in mind that Mars is dry (so is the moon). Why do you think scientists are concerned that static electricity will be a much bigger problem for astronauts than it is for people here on Earth? (4 points)

The drier the climate the more present static electricity is. The soil is so dry and if an astronaut were to walk on it a lightning bolt would zap his electrons.

3 points

4. In the future, as astronauts walk across the Martian surface, they will acquire a static charge.
A. What will this create around them? (2 points)

It will create an electric field.

2 points

B. If they accumulate a lot of charge, what might happen to sensitive electronics (in air locks, perhaps) as the astronaut approaches? (2 points)

The charge may send a bolt of lightning to the electrons and fry all of them.

    2 points

Current and Circuits:
5. Fuel, like diesel and propane, is too heavy for the Mars mission to carry much, if any, of it. So power is likely to be provided by a solar array instead of a generator. The energy collected from the solar arrays will be stored in large battery banks. Most of the circuits will have a load of about 12 Ω. If 4 A is needed to run the equipment, what voltage does the battery bank need to be? (4 points)

48v=12^4b or 48v=20,736b

   0 points

6. Design these circuits for use at the Mars station. Show sketches of the circuit. Then complete the math. (12 points)
A. A 12-V battery, running a motor. There's also a switch in the circuit so the motor can be turned on and off. Show this, too. If the motor has a resistance of 12 Ω, how much current goes through the motor? (4 points)

For every one amp= 12/12

   1 point

B. One 24-V battery, charging up the Mars Rover. If the Rover has 120 ohms of resistance, how much current flows through it? (4 points)

for every 2 amps= 24/120 or 2a=0.2

4 points

C. Four 12-V batteries, combined to produce a total of 48 volts of potential, running the heating system. (On a warm day, it might reach 60°F on Mars!) This circuit needs a circuit breaker, represented as a resistor. So put one in.
What is the voltage difference across the heater? If the heater has a 12 Ω resistance, how much current goes through it? (4 points)

48 across the heater and 4a through the heater would be 48/12

     0 points

Magnetism
7. The floors of the future Mars Station will be metal-stainless steel, in fact. The gravity on Mars is about one-third of that on Earth, so when the astronauts walk they will bounce along.
A. To keep them from bobbing so much, what can they do to the bottoms of their boots? (2 points)

add magnets to the bottom of the boots

   2 points

B. One of the future astronauts must extend a probe outside the station to monitor the atmosphere every hour. But she gets tired of manually pushing out the probe extension every hour. She has access to batteries, some wire, some iron, a timed switch, and some permanent magnets. What can she make so that she doesn't have to operate the probe by hand every hour? What purpose does the timed switch serve? (6 points)

the electric switch that allows all connected devices to receive and get power.

2 points

C. As the teams start exploring the surface of Mars in the future, they will notice that they cannot use compasses for navigation. What is necessary for a compass to work as a navigation tool? Since compasses do not work on Mars, what can you conclude is true of Mars? (6 points)

No, it should not because mars doenst have a magnetic field like earth's that is generated by the core.

4signals. All they will hear is static. Considering that wireless communications are electromagnetic in nature, why do you think this would occur? (4 points)

Sand storms cause a lot of the static electricity from all of the tiny dust particles rubbing together and it would completely block the electromagnetic transmission.

    

4 points
--

  

[as3...@epiccharterschools.org]

On Tuesday, December 18, 2012 at 12:18:58 PM UTC-6, ndan...@gmail.com wrote:
> 6.4.2 Practice: Electricity and Magnetism
>
> Practice Assignment
> Physical Science (S1744040)
>
> Nestor Cruz
> Points possible: 50
>
> Date: 12/18/12

> dtdyhtdd gdd y o u a r e s t u p i d