How do we get to Energy?

There is a progression which will take us from Position to Energy. This progression goes through Velocity, Acceleration and Force. This progression is a “trip” that will give you sever

• Velocity is needed to get from the location where you are to the location where you want to be.
  • A position is a location.
  • Distance is the difference between the values assigned to the two positions.
• Acceleration is needed to change Velocity.
• A Force is needed to give Acceleration to a Mass.
• Energy is needed to maintain a Force as it moves over a Distance.

Bonus Features

Origin

Take some time to think about position and location. Inagine that you live on a road with mile markers and that there’s a mile marker by your house, “05”, and that there’s a mile marker by your friend’s house, “07”. Your mind is so fast, you knew your friend lives two miles away from you before I had a chance to finish saying this sentence.

Distance = position2 – position1

2 m = 7 m – 5 m

The idea of an origin is born when you get to the position marked by “00” and you think “this place is important because this is where it started.”

Velocity

Velocity has units and the number may include a negative sign. This is how it is different from speed.

For simplicity, we are not worrying about details such as you didn’t travel at the same velocity the whole time. Your physics textbook may talk about average velocity and define it the same as what we show above.

At a velocity of 15 mph you will get from your house to your friends house in 8 minutes.

To get from your friend’s house to your house in 8 minutes, you need to travel with a velocity of -15 mph. Does it make sense that the negative sign changes the direction of travel?

We made two choices, the location of the origin, and the direction for positive, and from that we got that your house is at mile marker 5 and your friend’s house is at mile marker 7.

You are granted certain powers in the realm of physics, and you can put the origin where you want it, and also choose which direction do the positive direction. Maybe you decide to put the origin at your house and have the positive direction point towards your friend’s so that your friend is now at mile marker “02”. Does it make sense that the location that was previously the origin is now a location we would designate by “-05”?

Acceleration

Acceleration is a change in velocity per unit time. This can become change in position per time squared if the units for time in the two places are the same. Just make sure if you have seconds and hours that you convert one to the other.

Force

For a given force, the I’m out to acceleration if we get will depend on the mass. It should make sense that increasing the mass will decrease the acceleration for a given amount of force.

Energy

Energy is a calculation of the requirenent to exert the Force that moves an object a known distance.

This careful wording is needed because energy and work share the same units. From one point of view it took so much energy for the whatever to happen. From another point of view so much work was done when that whatever was done.

We could say that we are done at this point. Would you like to look at one more equation?

Two different equations for energy will be shown, and at the end we will show that in the end they both have the same units

We could say

Appendix A – Average Velocity

As a child, we took car trips in the summer to visit family, and even though we drove at near 60 mph, when we calculateod distance traveled divided by the amount of time we calculated 50 mph.

We lost time when the car needed gas and when we needed to stop for a meal.