1. Calculating Potential and Kinetic Energy Follow the steps

2. Equations Potential Energy (E p )=Weight x Height Or: Kinetic Energy (E k )=1/2 (mass x velocity 2 ) SHOW YOUR WORK FOR EACH STEP EPEP Wt. Ht.

3. Let’s calculate some SIMPLE kinetic energy equations: What is the kinetic energy of a 0.5kg soccer ball that is traveling 3 m/s? E k = ½ (m x v 2 ) E k = ½ (.5 x 3 2 ) E k = ½ (.5 x 9) E k = ½ (4.5) E k =2.25 J What is the kinetic energy of a 1 kg strawberry pie that is thrown across the lunch room with a speed of 2 m/s? E k = ½ (m x v 2 ) E k = ½ (1 x 2 2 ) E k = ½ (1 x 4) E k = ½ (4) E k =2 J

4. A shot putter heaves a 8 kg shot with a velocity of 7.5 m/s. What is the form of energy? ______________ Calculate it. E k = ½ (m X v 2 ) E k = ½ (8 x 7.5 2) E k = ½ (8 x 56.25) E k = ½ (450) E k = 225 A jogger with a mass of 65 kg is traveling at a speed of 2.5 m/s. What is the form of energy? ________________ Calculate it. E k = ½ (m X v 2 ) E k = ½ (65 X 2.5 2) E k = ½ (65 x 6.25) E k = ½ (406.25) E k = 203.125

5. An apple in a tree has a mass of 45 kg and is hanging in a tree 22 meters above the ground. The apple has _____________ energy. Calculate it. E p = Wt. X Ht. E p = 45kg x 22m =2025 J The same apple falls from the tree at 4 m/s. What type of energy is described? _______________ Calculate it. E k =1/2 (m x v 2 ) E k = ½ (45 x 4 2 ) E k = ½ (45 x 16) E k = ½ (720) E k = 360 J

6. Determine the potential energy of roller coaster that has a first hill of 2000m tall and coaster Cars with a mass of 625 kg. E p = Wt. x Ht. E p = 625 x 2000 E p = 1,250,000 J If the roller coaster is traveling at a speed of 20 m/s at the bottom of the first hill, determine the coaster’s kinetic energy. E k = ½ (m x v 2) E k = ½ (625 x 20 2) E k = ½ (625 x 400) E k = ½ (250,000) E k = 125,000 J Thinking question: What would happen to the kinetic energy of the coaster if the mass of the coaster car doubled?

7. CHALLENGE question! A bike rider approaches a hill with a speed of 8.5 m/s. The total mass of the rider and the bike is 85 kg. 1.What is the kinetic energy of the bike and rider? 2.The rider coasts up the hill. Assuming there is no friction, at what height will the bike come to a stop?