Answer:
D. 1.4*10^-1 seconds
Step-by-step explanation:
We know that distance = rate * time
We know the rate = 3.00 • 10^8 meters per second
and the distance =4.2*10^7 meters
distance = rate * time
4.2*10^7 meters = 3.00 • 10^8 meters per second * time
Divide each side by 3.00*10^8
4.2*10^7 /3*10^8 = 3.00 • 10^8/3*10^8 * time
4.2*10^7 /3*10^8 = * time
4.2/3 * 10^7/10^8 = time
When we divide exponents of the same base, we subtract the exponents keeping the base
1.4 * 10^(7-8) = time
1.4 * 10^-1 seconds = time
