Mechanical Energies November 16, 2010

In class, we were given whiteboards a

nd told to write the systems for the following situations:

1. A person is being dragged across a rug.

2. A hot air balloon rising up into the air.

3. Someone bouncing on a pogo stick.

4. A car going faster and faster.

The answers we came up with in our class discussion we

re:

#1 the system was the earth, person being dragged, and the rug.

#2 the system was the earth, hot air balloon.

#3 the system was the pogo stick.

#4 the system was the car.

Next we had to find the equation for work and what the negative signs means using the table

The equation is force * displacement = work

The negative sign means that you are applying a lot of opposite force.

After we did this we compared answers with two other groups. Our answers all agreed with each other.

Then we had to fill in this table.

Today in class I learned much more about systems because that was a topic that was a little confusing for me. I hope this blog helped teach you more about systems and mechanical energies.

-JM