Energy Resources
They can be replaced over short periods of time
Mechanical (kinetic + potential), thermal, electromagnetic, nuclear, electrical, chemical
What are kinetic and potential energy?
KE - energy of motion
PE - energy of position/still objects
What are the equations for kinetic and potential energy?
KE = 1/2*m*v2
PE = m*g*h
What makes energy resources nonrenewable?
They take a long time (thousands to millions of years) to replace
What is thermal energy?
Heat energy
What units are used to measure energy?
Joules
What does "v" stand for in the equation for kinetic energy?
Velocity or speed
What are fossil fuels made from?
The remains of dead organisms (plants & animals)
Mechanical energy equals _____________ + _______________.
KE + PE
A frog is about to jump. Does it have kinetic or potential energy?
Potential energy
Calculate the PE of a 1 kilogram teddy bear setting on top of a 2-meter tall bunk bed. (Assume gravity is 10 m/s2.)
20 Joules
Name four renewable resources.
Solar/sunlight, hydroelectric/water, wind, nuclear fusion, geothermal, biomass (answers may vary)
Give an example of something with chemical energy.
Answers may vary - ideas are matches, firewood, and food
A scoop of ice cream falls off a cone. Does it have mostly kinetic or potential energy as it falls?
Kinetic energy
Calculate the kinetic energy of a 50-kilogram man running at a speed of 8 m/s.
1600 Joules
Name four nonrenewable resources.
Coal, oil, natural gas, uranium (answers may vary)
Fusion & fission
Name an example of a situation where an object can have both kinetic and potential energy.
Answers may vary. Here are some ideas:
- A ball is tossed into the air and has different amounts of kinetic and potential energy as it first rises, then falls
- A fan is blowing but could be blowing faster
A 30-kilogram canoe is floating downriver at a speed of 2 m/s. What is its kinetic energy?
60 Joules