A student runs 222 m at a speed of 7 m/s and then turns around and jogs at 8 m/s for 2 seconds. How far from the starting position does the student end up?

Answer 1

(0 m) A------------------------------------------------------------------------------------------------------------------------B (222 m)

C---------B

8 m/s x 2 s = 16 m

A students goes 222 m in one direction. Student's speeds is immaterial here.

Then student turns around and jogs for t=2 seconds at a speed of v=8 m/s.

The distance traveled in reverse direction is d = vt = 8 m/s x 2 s = 16 m.

So the net distance of the student from starting position is d = 222 m - 16 m = 206 m

Answer 2

The student initially runs 222 meters from their starting position. It does not matter for this question what their speed was for this initial 222 meters, since we are looking for final displacement.

The student then turns around and runs for 2 seconds at a speed of 8 m/s. Using our kinimatics equation ( Δx=v_it+1/2at², which simplifies to Δx=v_it since there is no acceleration) we get a distance traveled of -8*2=-16 meters. Notice the 8 is negative since the student is running in the opposite direction from the one he or she started in.

We then add the two distances together to get the final displacement of 222 +(-16) = 206 meters from the initial starting position.

Answer 3

Because we are trying to find distance, we do not care about the speed during the 222 m run. That is useless information.

After the student turns around, they run 8 m/s for 2 seconds.

8 meters per second means that every second, they jogged 8 meters. If they jogged for 2 seconds, it means they went 8*2 = 16 meters.

So, they went 222 meters forward, then 16 meters backward. Final distance from starting position is just the distance forward minus the distance backward. 222 m - 16 m = 206 m

Answer 4

So you need to find out, how much distance student ran when he turn around. To do that, we can use distance = Speed X time.

Distance he traveled when turns around is 8m/s X 2s = 16m

Distance from starting point will be = 222 - 16 = 206 m .