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

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

Explanation:

Speed is defined as the ratio between the distance covered by an object and the time taken to cover that distance:

A varying speed means that the speed is not constant, but it is changing over time. Let's analyze each option:

a car traveling the speed limit --> NO. The car is travelling always at the same speed, so its speed is constant

a fish moving at 2 m/s for 5 minutes --> NO. The fish is always moving at the same speed, so its speed is constant

a bird flying at 10 m/s for 10 seconds --> NO. The bird is flying always at the same speed, so its speed is constant.

a car slowing from 60 m/s to 0 m/s --> YES. The car is changing its speed from 60 m/s to 0 m/s, so this represents a varying speed.

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.