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A2 Physics Unit 4Jan 2010 Multichoice
KS5 A2 PHYSICS 2450Mr D Powell
Raw Marks....
A =B =C = D = E = U =
Mr Powell 2008Index
C
Ft=mv-mu
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B
v = 2x10-4 m3s-1 / 7.2x10-4m2 = 0.2778ms-1
mass per second = 1000kgm-3 x 2x10-4 m3s-1 = 0.2kgs-1
mv = 5.6 x 10-2
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D
Inelastic means that you lose some KE to thermal/sound in the smash
But you always conserve mass and total energy and momentum in any collision
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A
=v/r = (6400 x103 x 2/ 24 x 602)/ (6400 x 103)
D
FBI for C
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B........
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B
Reason out what is happening to M on spring about a point. Time for cycle is down, up past zero to top and down to zero. i.e. 0.5s x 4 = 2s A is only halfway down
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A Why?
B – it is in phaseC – It is the reverse!D – can happen in chemical or electrical systems as well
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A
Changes cancel out
1
4
4
)2(
22
22
'
'
221'
221'
F
F
r
mmF
r
mmGF
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D
Look at idea of velocity in circle v=r
Force on moving object in circle is F=mv2/r
GM
RT
TR
GMF
fR
GMF
R
fmR
R
GMmF
rv
rv
32
2
2
3
223
22
2
222
2
4
4
)2(
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B
1. Use formula for gravitation field on Earth.
2. Plug in new case then divide 2 by 1 to cancel all terms and give x2y
G
rgM
gr
GM
EEE
2
2
G
rxygM
gr
GM
gr
GM
EEP
p
P
P
22
2
2
1
2
yxM
MGrgGrxyg
M
M
G
rgM
G
rxygM
E
P
EE
EE
E
P
EEE
EEP
2
2
22
2
22
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D
Think of formula...
The gravitational potential (V) is the potential energy (U) per unit mass:U = mV where m is the mass of the object. The potential energy is the negative of the work done by the gravitational field moving the body to its given position in space from infinity
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A
Think of new situation and plug in numbers4
1
)2(
5.02
4
'
221'
20
21
F
r
QQF
r
QQF
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C 1. Work is only done then moving towards or away from electrode.
2. Equipotential means no PD between points
3. Hence no work against the field
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B
E-field is uniformD = ½ then V = ½ to cancel
d
VqF
qEFd
VE
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C
E=V/d
Field is 1NC-1
Electric Potential is 1JC-1
V
d
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C1. Energy = ½ mv2 this is converted to potential energy V at point
P
2. There is no way that total energy can be zero at this point or it would simply sit there and not reverse direction!
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D
........
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B
CV=QQ=ItCV=ItCV/I =t
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D
Look at equations Q = CV & E = ½CV2 Q V , E C
Now put in values ratios are 1000: 100 in formula
Both come out as 10:1 X:Y
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D
F=BILF = 0.2T x 8A x 0.4mF = 0.64N
Electrons = 8 x 1028 electrons/m3 x (1x10-6m2 x 8 x 0.4m)
Force per electrons = 2 x 10-23N
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C
Same plane so no effect
Br = mv / Bq
r m only correct one!
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A
Using formulae for induced e.m.f
Rearrange to second line....(mine complex version!)
BAN
t
tBAN
sin
sin
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A
1. Conducting Rod of length l moves through magnetic flux density (field strength per unit area) B at constant speed v....
2. Distance travelled by rod is v∆t
3. Area of flux it cuts is lv∆t.
4. Magnetic flux = = BA = B x lv∆t
5. Faraday law states e.m.f = ∆/ ∆t = Blv∆t/ ∆t = Blv6. e.m.f = 1x10-5T x 60m x 150ms-1 = 0.09Tm2s-1
= 0.09 Vsm-2m2s-1
= 0.09V