a and b are clearly wrong. You have multiplied instead of dividing. Read the hint.
When you divide, you subtract exponents, not add.
Radio signals travel at a rate of 3*10^8 meters per second. How many seconds would it take for a radio signal to travel from a satellite to the surface of Earth if the satellite is orbiting at a height of 4.2*10^7 meters? (Hint: Time is distance divided by speed.)
a. 1.26*10^16 seconds
b. 1.26*10^15 seconds***
c. 1.4*10^1 seconds
d. 1.4*10^-1 seconds
3 answers
Your answer would be -1, because you are subtracting 8 from 7.
Your answer would be -1, because you are subtracting 8 from 7. so it is D.