Question

Victoria is looking to the north. Lightning bolt 1 strikes a telephone pole 450 m from her. Lightning bolt 2 strikes a tree 1.2 km from her. Victoria sees the telephone pole strike 2 micro-seconds before the tree strike.

a. How long does it take the light from each strike to reach Victoria?

b. According to Victoria, were the lightning strikes simultaneous?

c. If they weren’t simultaneous, which happened first and what is the time difference between the two strikes?

Answer 1

a)

Time (pole) = distance / speed = 450 m / 300000000 m/s ==> 1.5 microseconds

Time (tree) = distance / speed = 1200 m / 300000000 m/s ====> 4 microseconds

b)

If the lightnings would have been silmultaneous the the difference between the times of tree and pole should have been 2 microseconds (according to the question).

here the difference is 2.5 microseconds.

Hence both the flashes of lightning were not simultaneous.

c) The lightning on tree struck first and after 0.5 microseconds, the other lightning struck the pole.