Asister spins her brother in a circle of radius r at angular speed wi. then the sister decreases her angular speed
to wi, with the same radius. how does the magnitude of the brother's centripetal acceleration change when the
sister slows down?

The change in the centripetal acceleration of the brother,

                               Δa = V₂²/R - V₁²/R

Explanation:

Given data,

A sister spins her brother in a circle of radius, R

The angular velocity of the brother, ω₁ = V₁/R

The angular velocity of the brother, ω₂ = V₂/R

The centripetal acceleration is given by the relation

                                 a = V²/R

Therefore change in the centripetal acceleration of the brother,

                              Δa = V₂²/R - V₁²/R                                    

what was the answer?

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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