Answer;
= 21333 Nanoseconds
Explanation;
Distance = Speed x Time
S = V x T
( Here S = 6.40 km = 6400 m, V = 300000000 m/s, T = ?)
6400 = 300000000 x T
6400 / 300000000 = T
=> T = 0.000021333 seconds
Convert seconds to nanoseconds
1 second = 1000000000 nanoseconds
Therefore,
T = 0.000021333 x 1000000000 nanoseconds
T = 21333 Nanoseconds
