1. Which Path Requires the Most Energy?
Suppose that a car traveled up three different roadways (each with varying incline angle or slope) from the base of a mountain to the summit of the mountain. Which path would require the most gasoline (or energy)?

2. Work-Energy Principle
In order to transfer energy to an object, you have to exert a ___________ on that object
Force

3. Work-Energy Principle
The amount of energy transferred by a force is called the w__________ d_________ by that force.
work done
WORK DONE= ENERGY TRANSFERRED

4. Work-Energy Principle
Whenever w_____ is done on an object, it’s energy changes...the energy is t________
to that object
Work (F•d)
transferred

5. Work-Energy Principle

6. Work-Energy Principle
This actually a special case of the Conservation of Energy
Formulas:
Worknet =ΔKE
=KEf- KEi
= ½mv²f- ½mv²i
F•d = ΔKE

7. Work-Energy Principle

8. Work-Energy Principle
#10 Homework
Worknet= ΔKE
F•d = ½mv²f- ½mv²i
A 13g bullet is accelerated in a rifle barrel 46.8 cm long to a speed of 522 m/s, use the work-energy theorem to find the avg Force exerted on the bullet while being accelerated

9. Work-Energy Principle
#9 Homework
Worknet= ΔKE
mgh = ½mv²f- ½mv²i
A 0.8 kg rock slides horizontally off a table from a height of 1.2 m. The speed of the rock as it leaves the thrower’s hand at the edge of the table is 2 m/s. 1) Solve for time
What is the KE of the rock just before it hits the floor?