g A person exploring a deep cave system becomes injured and needs to be rescued. The fastest way to get them is to pull them straight up out of the cave through a small opening just overhead, using a motor-driven cable. The lift is performed in three stages, each of them 10 m in height (total of 30 meters to extract the person). In the first stage, the person is accelerated to a speed of 5 m/s. They are then lifted at constant speed of 5 m/s, then in the last stage they are slowly decelerated to zero speed. If the person weighs 80 kg, how much work is done in each stage

1. W = 8848 J

2. W = 7848 J

3. W = 6848 J

Explanation:

The work (W) can be found using the following equation:

Where: E(k) is the kinetic energy and E(p) is the potential energy

Now let's find the work for every stage.

Stage 1:

Where: m is the mass, g is the gravity, h is the height, v is the speed  

Stage 2:

The kinetic energy is equal to zero because the acceleration is constant.

Stage 3:

I hope it helps you!

hello there!

your answer is a “generator”

a generator does not create energy but instead it transforms it.

it’s basically a motor working in reverse.

be subject to a force andchange its motion