An asteroid is heading toward Mars at the rate of 7.7×10^4 mi./hr. If the asteroid is 3.311×108 miles away from Mars, how many hours will it be before it hits Mars? Write the answer in scientific notation, expressed to the exact decimal place.(1 point)
To find the number of hours it will be before the asteroid hits Mars, we divide the distance between Mars and the asteroid by the speed of the asteroid:
3.311×10^8 miles ÷ 7.7×10^4 mi./hr.
To divide numbers in scientific notation, we subtract the exponents and divide the coefficient:
(3.311 ÷ 7.7) × 10^(8 – 4)
= 0.429 × 10^4
To express this number in scientific notation to the exact decimal place, we have to move the decimal point of 0.429 to the right one place, so the coefficient is 4.29:
4.29 × 10^3
Therefore, it will be 4.29 × 10^3 hours before the asteroid hits Mars.