232k views
0 votes
Light travels at 3.0 x 108 km/s. How far does light travel in 5 minutes? A) 1.5 x 1010 km B) 1.5 x 1011 km C) 9.0 x 109 km D) 9.0 x 1010 km

User JHarnach
by
8.5k points

1 Answer

3 votes
D) 9.0 x 10^10 km This is more an exercise in handling scientific notation than anything else. Since we have the distance that light travels in 1 second and we want to calculate how far it travels in 5 minutes, we must first calculate how many seconds are in 5 minutes. Simply multiplying 5 by 60 gives us 300 seconds. Now we need to multiply 300 by 3.0x10^8 km. So 300 * 3.0x10^8 = ? We could first convert 300 into scientific notion, but it's easier to just leave it along and assume that it's 300 x 10^0. So 300 times 3 is 900. And since 0 plus 8 is 8, we have as the answer: 900 x 10^8 But we're not done. The significand has to be greater than or equal to 1 and less than 10. So let's divide 900 by 100 and add 2 to the exponent. So we get 9 x 10^10 Finally, since our data had 2 significant figures, our result should have that as well. So let's add the 2nd digit getting: 9.0 x 10^10 So we know that light travels 9.0x10^10 km in 5 minutes, and that answer matches option "D" from the available choices.
User Luca Bezerra
by
8.0k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories