Question

The team monitoring a space probe exploring the outer solar system finds that radio transmissions from the probe take 4.22 hours to reach earth. how distant (in meters) is the probe?

Answer 1

Radio transmissions are electromagnetic waves, so they travel at speed of light:
$c=3 \cdot 10^8 m/s$

The time taken for these radio waves to go from the probe to Earth is
$t=4.22 h =15192 s$

Therefore, we can use the basic relationship between space, time and velocity to find the distance covered by the radio waves in this time, which corresponds to the distance of the probe from Earth:
$S=vt=(3 \cdot 10^8 m/s)(15192 s)=4.56 \cdot 10^{12} m$