1. David and Mat are training for the swimming team, swimming lengths of 25 metre pool. Mat swims four lengths in 125 seconds at a steady sped. A)After four lengths, how far has Mat swum? B)After four lengths, what is Mat's displacement?

a) Mat swum 100 meters.

b)after 4 length , Mat's displacement is zero.

Explanation:

As given, Mat and David are training for the swimming team , and Length of 1 side of the pool is 25 meter.

As swimming pool will be a cube or a cuboid , so it has only 4 sides.

a)

1 length = 23 meter

⇒4 length = 4×25 = 100 meter

So, Mat swam 100 meters.

b)

As after swam 4 lengths of the pool, Mat reaches to its initial position i.e Mat come back to its starting point.

As Displacement is always measures from the starting point.

So, after 4 length , Mat's displacement is zero.

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.