Question

The moon is 4x10^8m from the earth, a radar signal transmitted from the earth will reach the moon in about how many seconds?

Please answer with full steps.

Answer 1

velocity of signal = velocity of light =3×(10)^8 m
time = distace / velicty = 4×10^8/3×10^8= 4/3 sec

Answer 2

we know that

speed = distance / time

or

time = distance / speed

here,

distance between earth and moon = 4 x 10^8m

speed of radar signal = 3 x 10^8m/s [speed of light ]

so,

the time taken by radar signal to reach the moon will be

t = 4 x 10^8/ 3 x 10^8

thus,

t = 1.33 s