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An estimate of the energy stored in a 1.5V torch battery is?

a- 10^4J
b- 3x10^5J
c-10^7J

Please explain how you got your answer, thanks :smile:
Reply 1
Avatar for PhysGeek
PhysGeek
bump because i also have no idea!!
Moved to Physics section :smile:
Reply 3
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PhysGeek
It was A xx


Posted from TSR Mobile
Reply 4
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YellowNinja
OP
5
Posted from TSR Mobile

I need working out :/
Reply 5
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peterith
7
What formula can we use to estimate this potential energy?

E=Vq
E=VIt
E=Pt ??

Maybe we need to estimate first how long the battery can last for. Also estimate its "watt". haha i have no clue.
well treating is like a fermi question (see another recent post)

estimated power consumption of a torch lamp (obsolete filament type) ~ 0.5W
estimated battery life ~ 6h = 21600s

Power=Energy/Time
Energy=Power * Time
=21600/2
=10800

assume 2 batteries in series, so energy per battery is...
10800/2 = 5400 = 5.4 * 10^3 J

which is closest to A

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