Which forces keep the bottle moving
round and round?

Centripetal force

Explanation:

The force that keeps a bottle moving round and round in circular motion is centripetal force.

Centripetal force is an inward directed force that keeps a body in circular motion. This force keeps a body moving along a circular path.

To find the force, we use the expression below;

     F =

F is the centripetal force

m is the mass of the body

v is the velocity

r is the radius

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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