Question

A laser beam takes 15 ms to travel from a rocket to the reflective surface of a planet and back to the rocket. How far is the rocket from this planet's surface

Answer 1

Step-by-step explanation:

It took 7.5 ms or
`7.5×10^(-3)\:\text{s}` for the laser beam to reach the planet's surface. Since the speed of light is
`3×10^8\:\text{m/s}`, the distance is

`d = vt = (3×10^8\:\text{m/s})(7.5×10^(-3)\:\text{s})`

`\:\:\:\:=2.25×10^(6)\:\text{m}`