please help me solve this problem...please do help. (1 Viewer)

Haku

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please help me do this question, i got now idea where to start...

please do a,b,c,and d. please list all formulas used and calculations.
i know its really troublesome, but thanks a mountain for the helps....
 

physician

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after spending 20 minutes trying to figure it out... i figured my mind is not all that physics-ish at the moment

however... i only managed to go as far as figuring out the force.... which may be of some help.. that's if the force is right... but it if it helps it will only help in b and maybe d

anyways...

u have F=Bqv

F/q = Bv

since intensity = 10000 NC-1

therefore F/q = 10000 NC-1

therefore Bv = 10000 NC-1

now: F/-1.6(10)19 = 10000 NC-1

so: F = -1.6(10)23

i've probably just wasted my time doing this becaue its probably makes no sence... but hey i though i would at least try to help....

good luck... by the way i'll take it to my physics teacher and try to get him to solve it

ahhh... i just figured this is in the 'ideas to implemenation section'... well if its related to that module... then it explains everything...

i'm not up to it yet.....lol.... sorry
 
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helper

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No magnetic field in this question.

a) E=V/d calculate E
F=Eq Calculate F
F=ma calculate a
v^2=u^2 + 2as Calculate v, remembering u=0

b) F=Eq Calculate F
Calculate F(T)= F electric + gravitational
F(t)=F(E) + mg
F(t)=ma calculate a

c) Parabolic as there is a constant force in the vertical direction

d) s=ut+0.5at^2 =ut as no horizontal acceleration. Use v from a for u
 

physician

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helper said:
No magnetic field in this question.

a) E=V/d calculate E
F=Eq Calculate F
F=ma calculate a
v^2=u^2 + 2as Calculate v, remembering u=0

b) F=Eq Calculate F
Calculate F(T)= F electric + gravitational
F(t)=F(E) + mg
F(t)=ma calculate a

c) Parabolic as there is a constant force in the vertical direction

d) s=ut+0.5at^2 =ut as no horizontal acceleration. Use v from a for u
ahh fewww! i though i was supposed to know how to do this...

i'm still up to module 2.... so yeh... but can't wait until i learn this stuff....
 

aaaman

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physician said:
ahh fewww! i though i was supposed to know how to do this...

i'm still up to module 2.... so yeh... but can't wait until i learn this stuff....
module 2? or u mean core topic 2 bcoz if ur up 2 da second topic by now ur really behind
 

KFunk

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Our clas hasn't quite finished our second topic yet. My chem class is even further behind.
 

physician

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aaaman said:
module 2? or u mean core topic 2 bcoz if ur up 2 da second topic by now ur really behind
its unfortunate but it's soo true.. we have only completed space and almost done with motors and generators... and that's pritty much it...

because of this.. i still havn't had my half yearly which has been delayed to week 6

and now we have to have an extra class on fridays because we're really behind....

but hey my teacher still thinks we'll have 4 weeks revision before StuVac....

oh well such is life... but i'm not too worried because we're going really well with regards to 2 and 3 units maths and as for chem... i think we're moving at a terrific pace.... so yeh... if it wasn't for that i'd probably have dropped physics along time ago....
 

rnitya_25

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our class is quite ahead....we're half way thru ideas 2 implementation...really quite interesting stuff....
 

Jago

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We haven't finished motors either. Still doing transformers.
 

Haku

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good to here that so many people is actually behind...hehe so am i
 

Haku

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helper said:
No magnetic field in this question.

a) E=V/d calculate E
F=Eq Calculate F
F=ma calculate a
v^2=u^2 + 2as Calculate v, remembering u=0

b) F=Eq Calculate F
Calculate F(T)= F electric + gravitational
F(t)=F(E) + mg
F(t)=ma calculate a

c) Parabolic as there is a constant force in the vertical direction

d) s=ut+0.5at^2 =ut as no horizontal acceleration. Use v from a for u
for a) we do not know the distance between the parallel plates in the electron gun. the 2cm listed in the question is the length of parallel electric plates. also i dun get the equations for part b)

please elaborate a bit...thanks for ur time to answer the question. it was great help.
 

helper

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(a)
E=V/d
F=Eq=Vq/d
ma=Vq/d
a=Vq/(md)
v^2=u^2 +2as
v^2=2*Vq/(md)*s s and d cancel out.
v^2=2Vq/m

b) Force Electrical = Eq

Net Force = Sum of forces = Force electrical + Force Gravity
Net Force = Eq + mg
ma=Eq + mg
a= Eq/m + 9.8
 

Haku

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thanks "helper" for that, its really made sense.

but for part d, why do u employ that formula?
can't you use s=u*t? we know s to be 0.02m and (u) we know from part a...
i dun know if my thinking if right, just asking.

also could u elaborate a bit more on ur equation for part d, it has horizontal acceleration right? also for that formula how do u make t the subject of the equation?



please could u check my answers.
a) v= 1.9*10^7 m/s
b) a= 1.76*10^15 m/s/s

are those right?
 

helper

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nosadness said:
thanks "helper" for that, its really made sense.

but for part d, why do u employ that formula?
can't you use s=u*t? we know s to be 0.02m and (u) we know from part a...
i dun know if my thinking if right, just asking.
Because I'm an oldy who always goes back to the three base equations for unformally accelerated motion
v=u+at
s=ut + 0.5at^2
v^2=u^2 + 2as

All the others are derived from these based on these with assumptions like zero a etc.
You may find out in maths that you can also derive the equations from first principles

also could u elaborate a bit more on ur equation for part d, it has horizontal acceleration right?
No acceleration in the horizontal direction as there is no horizontal forces once it leaves the electron gun.

Just use s=ut, it is the same equation with the assumption a=0


please could u check my answers.
a) v= 1.9*10^7 m/s
b) a= 1.76*10^15 m/s/s

are those right?
That is what I came up with
 

Haku

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wow...i am finally getting something.

you are my hero "helper"...you are not an oldie at all.... hope my phy skill would improve to ur level.
 

tigerchenyanhu

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I think

for question one there is a quick way to do it
becasue w=qu and all the work done is transformed to the kinetic energy so w=qu=1/2mv^2 then u will get the same expression for v instaed of doing those elmination of d etc
 

Haku

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w=qu?

whats q stand for whats u stand for?

never seen that formula....
 

helper

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Should be W=qV
It isn't in the syllabus.
It comes from W=Fs
F=Eq
W=Eqs
E=V/d
W=Vqs/d

s/d =1

W=qV
 

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