Please help With 2 Electric Questions Please

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In summary, the conversation is about two physics questions involving potential difference and work. The first question asks for the speed of an electron after being accelerated through a potential difference, while the second question asks for the charge of a positively charged particle after achieving a certain speed through a potential difference. The conversation includes a hint on how to solve the first question and a solution for the second question. The charge of the electron is mentioned as being the elementary charge e = 1.602 x 10^-19 C.
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Please help With 2 "Electric" Questions Please

I don't want to bother you guys, but my little brother has an independent study unit due tomorrow and he can't seem to figure out these two questions. I'm not so great with physics since I'm taking biology related courses. Anyways the questions are as follows, i think they are actually very simple, but i just don't have the background to figure them out right now. So if anyone can post solutions to these, it'll help myself learn/understand it so i can relay it to my brother. thanks.

1. An electron has a mass of 9.11 X 10^-31 kg. Originally, it's at rest. What speed will the electron have after it is accelerated through a potential difference of 5.67 X 10^3 V?

2. A positively charged particle had a mass of 6.70 X 10^-27 kg. When it was accelerated through a potential difference of 4.50 X 10^3 V, it achieved a speed of 6.56 X 10^5 m/s. What charge did the particle have?

Thanks again =).
 
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  • #2
They are energy problems. Potential difference and work are related through

[tex]W = q \Delta V[/tex]

And work is related to change of kinetic energy through

[tex]W = \Delta K = \frac{1}{2}m(v_f^2-v_1^2)[/tex]
 
  • #3
hmm, interesting, based on the info that you have given, I've deduced that the answer to #1 can be obtained through:

q/(4.555X10^-31) = vf^2

where q is a charge in coulombs, and vf is the final velocity.

how do i figure what q is?
 
  • #4
[tex]\frac{2q\Delta V}{m} = v_f^2[/tex]

I get q(1.2447 x 10^-28) = vf^2.

The charge q is that of the electron. It is the elementary charge e = 1.602 x 10^-19 C.
 
  • #5
your info helped a lot thanks.
 

1. What are the two electric questions that need help with?

The two electric questions that need help with are not specified in the prompt, so it is difficult to provide an answer. However, some common electric questions may include topics such as circuits, voltage, current, resistance, and electrical safety.

2. Can you explain the difference between AC and DC electricity?

AC (alternating current) electricity is when the flow of electrons periodically changes direction, while DC (direct current) electricity is when the flow of electrons only moves in one direction. AC electricity is commonly used in households and businesses, while DC electricity is used in smaller devices such as batteries.

3. How does electricity flow through a circuit?

Electricity flows through a circuit when there is a closed loop or path for the electrons to move through. The flow of electrons is caused by a difference in voltage between two points in the circuit, and this difference is maintained by a power source such as a battery.

4. What are the safety precautions when working with electricity?

Some safety precautions when working with electricity include always turning off the power source before working on a circuit, wearing protective gear such as gloves and safety glasses, and avoiding contact with water or wet surfaces. It is also important to never touch a live wire or outlet with bare hands.

5. How can I calculate the power consumption of an electrical device?

To calculate the power consumption of an electrical device, you can use the formula P = VI, where P is power in watts, V is voltage in volts, and I is current in amps. You can find the voltage and current information on the device or by using a multimeter. Another way to calculate power consumption is by using a power meter or wattmeter.

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