ENERGY in space!

Two types of Energy
• Kinetic Energy

Kinetic or potential energy?
• Moving car
• Parked car
• Our Sun
• A tennis ball hanging from a string
• A baseball at the top of a hill
• A bucket of water???

How to find Kinetic energy
• If an object is moving we can find it’s kinetic energy!
• KE – Kinetic Energy (Joules)
• m – mass (Kg)
• V – velocity (m 2 /s 2 )

• Examples:
• Determine the Kinetic energy of a 500kg roller coaster train which moves at a speed of 20 m/s
• What is the speed of a 55 kg woman running with a kinetic energy of 412.7 J?
• The moon has a mass of 7.36 1022 kg and moves about the earth in a circular orbit of radius 3.80 108 m with a period of 27.3 days. Determine the kinetic energy of our moon! (hint: you’ll need to use the formula 2πr 2 )

How to find Potential Energy
PE = m x g x h
• PE – Potential energy (Joules)
• M – mass (Kg)
• g – acceleration due to gravity (m/s 2 )
• h – height (meters)
• Solve for m, g, and h!

PE = m x g x h
• A cat had climbed at the top of the tree.
The Tree is 20 meters high and the cat weighs 6kg. How much potential energy does the cat have? ( g=9.8m/s 2 )
• On a 3m ledge, a rock is laying at the potential energy of 120 J. What will be the mass of the rock.

What is the most common form of energy that we can feel on a daily basis?
• HEAT!
Temperature is a measurement of the average movement of molecules in a substance
• Heat is a measurement of energy in units of Joules!

• Which has more Kinetic Energy (heat)? Which is a higher temperature?
A B

Heat is transferred through
Convection, Conduction, and Radiation