The sound of thunder travels away from a lightning flash at 331metres/second. Joe sees a lightning flash and then hears thunder 12 seconds later. How far away is Joe from the lightning flash (nearest tenth of a km)

Question

anonymous · Answer

distance= v x t/2= 331x6=1986 m= 1.986 km

anonymous · Answer

i say t/2 because sound is go away and back

dumbcow · Answer

i disagree, in this case its 331*12 = 3.97 km

anonymous · Answer

I thought it was distance = speed x time

anonymous · Answer

@dumbcow: yeah I had that answer too

anonymous · Answer

oh yes

anonymous · Answer

i agree with dumbcow

dumbcow · Answer

btw round up to 4km
just looked at that part

anonymous · Answer

the speed of light is c = 3E8 m/s is time 1
time 2 is sound to observer at 331 m/s
if this is a standard physics problem the first time is very small and ignored and only the second is used.
distance= v x t= 331 x 12=3972 m= 3.972 km

anonymous · Answer

that is a bit confusing to me but i understand the last bit :)