Question

James covers a distance of 8 meters in the first second of a 100 meter race. Then, he sprints at a speed of 9 meters per second. How far is James from the finish line 9 seconds after the race has started? a. 11 c. 28 b. 20 d. 80

Answer 1

So James covers 8 meters in the first second....then he sprints 9 meters per second......
9 seconds after the race....so there are 8 seconds that he is sprinting 9 meters per second.....(8 * 9) = 72 meters....plus the 8 meters for the 1st second = (72 + 8) = 80 meters....
and if it is 100 meter race, and he has ran 80 meters, then that leaves 20 meters from the finish line....answer is D

Answer 2

Answer:

Option b. 20 meters

Step-by-step explanation:

James covers a distance of 8 meters in the first second of 100 meter race.

Then, he sprints at a speed of 9 meters per second.

We have to find how far is James from the finish line 9 seconds after the start of the race.

James covers distance in first second = 8 meters.

Time remaining in 9 seconds after running 8 meter = 9 - 1 =  8 seconds.

In another 8 seconds James covers the distance = speed × time

 = 9 × 8 = 72 meters

Total distance covered in 9 seconds = 8 + 72 = 80  meters

Distance remaining in 100 meter race after 9 seconds = 100 - 80 = 20 meters.

James is 20 meters far from the finish line 9 seconds after the race has started.

Option b. 20 meters is the answer.