The New Horizons probe flew past Pluto in July 2015. At the time, Pluto was about 32 AU from Earth. How long did it take for communication from the probe to reach Earth, given that the speed of light in km/hr is 1.08 * 109?

15944.6 sec

Explanation:

d = distance of Pluto from earth = 32 AU = 32 x 1.496 x 10¹¹ m

v = speed of light = 1.08 x 10⁹ km/hr = (1.08 x 10⁹) (0.278) m/s

t = time taken for the communication to reach from probe to earth = ?

Using the equation

d = v t

Inserting the values given

32 x 1.496 x 10¹¹ = ((1.08 x 10⁹) (0.278)) t

t = 15944.6 sec

t = 1.6 x 10⁴ sec