Which object has a varying speed? a bird flying at 10 m/s for 10 seconds a car slowing from 60 m/s to 0 m/s a car traveling the speed limit a fish moving at 2 m/s for 5 minutes

The car slowing from 60 m/s to 0 m/s

Explanation:

The bird flying at 10m/s for 10 seconds will have the same speed for those 10 seconds. So we can say it doesn't have a varying speed (During those 10 seconds, we don't have any information about what happens later).

The fish moving at 2m/s for 5 minutes will have the same speed for those 5 minutes. So we can say it doesn't have a varying speed (During those 5 minutes, we don't have any information about what happens later).

The car traveling the speed limit, we know that his speed is the speed limit. It doesn't change.

The car slowing from 60 m/s to 0 m/s needs to change his speed in order to go from 60 m/s to 0 m/s. The speed will decrease progressively until the car completely stops.

resonant frequency

increase masses, decrease separation