Electric Potential slowing a charged particle to a stop

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SUMMARY

The discussion centers on calculating the magnitude of an electric field required to stop a charged particle with a mass of 6.7 × 10–27 kg and a charge of 3.2 × 10–19 μC, moving at a speed of 4.8 × 105 m/s over a distance of 2.0 m. The correct approach involves using the equation ΔE.E = -q * (E.d). Participants identified a critical error in the charge unit, clarifying that μC should be converted to C for accurate calculations. The consensus is that the question was incorrectly stated, leading to confusion in the calculations.

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fight_club_alum
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Homework Statement


A particle (mass 6.7 × 10–27 kg, charge 3.2 × 10–19 μC) moves along the positive x-axis with
a speed of 4.8 × 105 m/s. It enters a region of uniform electric field parallel to its motion
and comes to rest after moving 2.0 m into the field. What is the magnitude of the electric
field?
a) 2.5 KN/C
b) 1.5 KN/C
c) 1.2 KN/C
d) 3.5 KN/C
e) 2.4 KN/C

Homework Equations


(delta)E.E = -q * (E.d)

The Attempt at a Solution


(1/2*(6.7*10^-27)*(4.8*10^5)^2)/( (3.2*10^-19) * 10^-6) *2)

The problem is that when I convert the charge from uc to c I get the answer but multiplied by a number like million and when I divide it by 1000 to get KN still the number remains multiplied by a factor of 1/10. On the other hand, if I leave the charge in uc I get the answer when I divide by 1000 as I should. I feel that I messed a step in the middle or there is a mistake in the question
Thanks in advance
 
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fight_club_alum said:

Homework Statement


A particle (mass 6.7 × 10–27 kg, charge 3.2 × 10–19 μC) moves along the positive x-axis with
a speed of 4.8 × 105 m/s. It enters a region of uniform electric field parallel to its motion
and comes to rest after moving 2.0 m into the field. What is the magnitude of the electric
field?
a) 2.5 KN/C
b) 1.5 KN/C
c) 1.2 KN/C
d) 3.5 KN/C
e) 2.4 KN/C

Homework Equations


(delta)E.E = -q * (E.d)

The Attempt at a Solution


(1/2*(6.7*10^-27)*(4.8*10^5)^2)/( (3.2*10^-19) * 10^-6) *2)

The problem is that when I convert the charge from uc to c I get the answer but multiplied by a number like million and when I divide it by 1000 to get KN still the number remains multiplied by a factor of 1/10. On the other hand, if I leave the charge in uc I get the answer when I divide by 1000 as I should. I feel that I messed a step in the middle or there is a mistake in the question
Thanks in advance
The smallest mass a particle (electron or proton) can have is 1.6 *10-19C. An ionized particle can have a multiple of it. So the μC should be a mistake.
 
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ehild said:
The smallest mass a particle (electron or proton) can have is 1.6 *10-19C. An ionized particle can have a multiple of it. So the μC should be a mistake.
yes, it turned out that the question is written incorrectly; (uc) should be (c) in this question.
Thank you so much
 
Think about the kinematic equations. What's the acceleration? Then use ##F=ma##
 
Miles123K said:
Think about the kinematic equations. What's the acceleration? Then use ##F=ma##
That was not the issue. See posts 2 and 3.
 

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