Kinetic & Potential Energy
energy that is stored
potential energy (it has the potential to do something)
Energy can be neither created nor destroyed–it is conserved by being transferred or transformed
Law of Conservation of Energy
This is done when a force that is applied to an object moves that object.
Work
Three types of simple machines
1. pulley
2. inclined plane
3. wedge
4. wheel and axle
5. lever
6. screw
speed with direction
velocity
energy due to motion of an object
kinetic energy
Photosynthesis is an example of this type of energy.
Chemical energy
Formula for calculating work
force x distance = work
F x d = W
A mover uses a ramp to load boxes into a moving van. This is an example of which type of simple machine?
Inclined plane (ramp)
Wheel and axle (cart to move boxes)
changing velocity in a positive or negative direction
acceleration
kinetic energy + potential energy = _________ energy
total energy or mechanical energy
Writing with your pencil is considered this type of energy
Unit for measuring work
Joules (J)
Using a knife to cut potatoes is an example of which type of simple machine?
Wedge
a horizontal line on a distance vs time graph represents this kind of velocity
no velocity; 0 m/s; no movement
Describe an example of an object that has maximum potential energy
Answers will vary, but an example would be a roller coaster at the top of a hill.
Two forms of energy that are usually less useful when using electricity to power our electronics.
Angie pushed a shopping cart with 60 newtons of force 200 meters down the aisle. How much work, measured in joules (J), did she do to move the cart?
12,000 Joules (J)
a measurement of the effectiveness of a simple machine
mechanical advantage
unequal forces that result in motion
unbalanced forces
Describe an example of an object that has maximum kinetic energy
Answers will vary but an example would be a roller coaster just before it gets to the bottom of a hill.
Describe 3 types of energy that can be seen when using a toaster to toast bread.
1. Thermal energy - to heat up the bread
2. Radiant energy - can be seen in the metal prongs that light up
3. Electrical energy - plugging in the toaster
4. Mechanical energy - using your hand to push down the button to toast
Katherine is pushing a box using a force of 195 N. If she pushes the box a distance of 500 m, how much work has she done?
97,500 Joules (J)
Describe a real world problem that a simple machine can solve that hasn't been mentioned yet
Answers will vary but an example would be a pulley used to raise a flag
a force of two objects sliding against one another
friction